diff --git a/.importlinter b/.importlinter
index 2d82ad7f1a..1f31cb4d3c 100644
--- a/.importlinter
+++ b/.importlinter
@@ -8,7 +8,7 @@ type = forbidden
 source_modules =
     openpilot.selfdrive.car
 forbidden_modules =
-    openpilot.common.params
+    openpilot.common
     openpilot.selfdrive.controls
     openpilot.system
     openpilot.body
@@ -23,6 +23,15 @@ ignore_imports =
     # remove these
     openpilot.selfdrive.car.interfaces -> openpilot.selfdrive.controls.lib.events
     openpilot.selfdrive.car.body.carcontroller -> openpilot.selfdrive.controls.lib.pid
+    openpilot.selfdrive.car.tests.test_docs -> openpilot.common.basedir
+    openpilot.selfdrive.car.docs -> openpilot.common.basedir
+    # car interface will not filter the speed
+    openpilot.selfdrive.car.interfaces -> openpilot.common.simple_kalman
+    openpilot.selfdrive.car.gm.interface -> openpilot.common.basedir
+    openpilot.selfdrive.car.interfaces -> openpilot.common.basedir
+    # these two will still live in openpilot, but require some modification
+    openpilot.selfdrive.car.fw_versions -> openpilot.common.params
+    openpilot.selfdrive.car.ecu_addrs -> openpilot.common.params
 
     # these are okay
     openpilot.selfdrive.car.card -> openpilot.common.swaglog
@@ -39,7 +48,5 @@ ignore_imports =
     openpilot.selfdrive.car.tests.test_car_interfaces -> openpilot.selfdrive.controls.lib.latcontrol_pid
     openpilot.selfdrive.car.card -> openpilot.common.params
     openpilot.selfdrive.car.tests.test_models -> openpilot.common.params
-    # these two will still live in openpilot, but require some modification
-    openpilot.selfdrive.car.fw_versions -> openpilot.common.params
-    openpilot.selfdrive.car.ecu_addrs -> openpilot.common.params
+    openpilot.selfdrive.car.tests.test_models -> openpilot.common.basedir
 unmatched_ignore_imports_alerting = warn
diff --git a/common/utils.py b/common/utils.py
deleted file mode 100644
index b9de020ee6..0000000000
--- a/common/utils.py
+++ /dev/null
@@ -1,11 +0,0 @@
-class Freezable:
-  _frozen: bool = False
-
-  def freeze(self):
-    if not self._frozen:
-      self._frozen = True
-
-  def __setattr__(self, *args, **kwargs):
-    if self._frozen:
-      raise Exception("cannot modify frozen object")
-    super().__setattr__(*args, **kwargs)
diff --git a/selfdrive/car/__init__.py b/selfdrive/car/__init__.py
index 0cdc6e9d8d..1da53d4cfa 100644
--- a/selfdrive/car/__init__.py
+++ b/selfdrive/car/__init__.py
@@ -9,9 +9,8 @@ import capnp
 
 from cereal import car
 from panda.python.uds import SERVICE_TYPE
-from openpilot.common.numpy_fast import clip, interp
-from openpilot.common.utils import Freezable
 from openpilot.selfdrive.car.docs_definitions import CarDocs
+from openpilot.selfdrive.car.helpers import clip, interp
 
 # set up logging
 carlog = logging.getLogger('carlog')
@@ -263,6 +262,19 @@ class CarSpecs:
     return replace(self, **kwargs)
 
 
+class Freezable:
+  _frozen: bool = False
+
+  def freeze(self):
+    if not self._frozen:
+      self._frozen = True
+
+  def __setattr__(self, *args, **kwargs):
+    if self._frozen:
+      raise Exception("cannot modify frozen object")
+    super().__setattr__(*args, **kwargs)
+
+
 @dataclass(order=True)
 class PlatformConfig(Freezable):
   car_docs: list[CarDocs]
diff --git a/selfdrive/car/chrysler/carstate.py b/selfdrive/car/chrysler/carstate.py
index 91b922c596..c8b084aa62 100644
--- a/selfdrive/car/chrysler/carstate.py
+++ b/selfdrive/car/chrysler/carstate.py
@@ -1,9 +1,9 @@
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from opendbc.can.parser import CANParser
 from opendbc.can.can_define import CANDefine
-from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.chrysler.values import DBC, STEER_THRESHOLD, RAM_CARS
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.interfaces import CarStateBase
 
 
 class CarState(CarStateBase):
diff --git a/selfdrive/car/conversions.py b/selfdrive/car/conversions.py
new file mode 100644
index 0000000000..b02b33c625
--- /dev/null
+++ b/selfdrive/car/conversions.py
@@ -0,0 +1,19 @@
+import numpy as np
+
+class Conversions:
+  # Speed
+  MPH_TO_KPH = 1.609344
+  KPH_TO_MPH = 1. / MPH_TO_KPH
+  MS_TO_KPH = 3.6
+  KPH_TO_MS = 1. / MS_TO_KPH
+  MS_TO_MPH = MS_TO_KPH * KPH_TO_MPH
+  MPH_TO_MS = MPH_TO_KPH * KPH_TO_MS
+  MS_TO_KNOTS = 1.9438
+  KNOTS_TO_MS = 1. / MS_TO_KNOTS
+
+  # Angle
+  DEG_TO_RAD = np.pi / 180.
+  RAD_TO_DEG = 1. / DEG_TO_RAD
+
+  # Mass
+  LB_TO_KG = 0.453592
diff --git a/selfdrive/car/docs_definitions.py b/selfdrive/car/docs_definitions.py
index a04653c140..f039fea9ac 100644
--- a/selfdrive/car/docs_definitions.py
+++ b/selfdrive/car/docs_definitions.py
@@ -5,7 +5,7 @@ from dataclasses import dataclass, field
 from enum import Enum
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
+from openpilot.selfdrive.car.conversions import Conversions as CV
 
 GOOD_TORQUE_THRESHOLD = 1.0  # m/s^2
 MODEL_YEARS_RE = r"(?<= )((\d{4}-\d{2})|(\d{4}))(,|$)"
diff --git a/selfdrive/car/filter_simple.py b/selfdrive/car/filter_simple.py
new file mode 100644
index 0000000000..0ec7a51562
--- /dev/null
+++ b/selfdrive/car/filter_simple.py
@@ -0,0 +1,18 @@
+class FirstOrderFilter:
+  # first order filter
+  def __init__(self, x0, rc, dt, initialized=True):
+    self.x = x0
+    self.dt = dt
+    self.update_alpha(rc)
+    self.initialized = initialized
+
+  def update_alpha(self, rc):
+    self.alpha = self.dt / (rc + self.dt)
+
+  def update(self, x):
+    if self.initialized:
+      self.x = (1. - self.alpha) * self.x + self.alpha * x
+    else:
+      self.initialized = True
+      self.x = x
+    return self.x
diff --git a/selfdrive/car/ford/carcontroller.py b/selfdrive/car/ford/carcontroller.py
index 9628dc651d..961d7086c4 100644
--- a/selfdrive/car/ford/carcontroller.py
+++ b/selfdrive/car/ford/carcontroller.py
@@ -1,9 +1,9 @@
 from cereal import car
 from opendbc.can.packer import CANPacker
-from openpilot.common.numpy_fast import clip
 from openpilot.selfdrive.car import apply_std_steer_angle_limits
 from openpilot.selfdrive.car.ford import fordcan
 from openpilot.selfdrive.car.ford.values import CarControllerParams, FordFlags
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.interfaces import CarControllerBase, V_CRUISE_MAX
 
 LongCtrlState = car.CarControl.Actuators.LongControlState
diff --git a/selfdrive/car/ford/carstate.py b/selfdrive/car/ford/carstate.py
index d7130681d4..ed707a5f78 100644
--- a/selfdrive/car/ford/carstate.py
+++ b/selfdrive/car/ford/carstate.py
@@ -1,7 +1,7 @@
 from cereal import car
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
-from openpilot.common.conversions import Conversions as CV
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.ford.fordcan import CanBus
 from openpilot.selfdrive.car.ford.values import DBC, CarControllerParams, FordFlags
 from openpilot.selfdrive.car.interfaces import CarStateBase
diff --git a/selfdrive/car/ford/interface.py b/selfdrive/car/ford/interface.py
index 54cf865109..b872be212b 100644
--- a/selfdrive/car/ford/interface.py
+++ b/selfdrive/car/ford/interface.py
@@ -1,7 +1,7 @@
 from cereal import car
 from panda import Panda
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import create_button_events, get_safety_config
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.ford.fordcan import CanBus
 from openpilot.selfdrive.car.ford.values import Ecu, FordFlags
 from openpilot.selfdrive.car.interfaces import CarInterfaceBase
diff --git a/selfdrive/car/ford/radar_interface.py b/selfdrive/car/ford/radar_interface.py
index 209bbebae3..f405373661 100644
--- a/selfdrive/car/ford/radar_interface.py
+++ b/selfdrive/car/ford/radar_interface.py
@@ -1,7 +1,7 @@
 from math import cos, sin
 from cereal import car
 from opendbc.can.parser import CANParser
-from openpilot.common.conversions import Conversions as CV
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.ford.fordcan import CanBus
 from openpilot.selfdrive.car.ford.values import DBC, RADAR
 from openpilot.selfdrive.car.interfaces import RadarInterfaceBase
diff --git a/selfdrive/car/gm/carcontroller.py b/selfdrive/car/gm/carcontroller.py
index cffaf4791d..dff280ed9a 100644
--- a/selfdrive/car/gm/carcontroller.py
+++ b/selfdrive/car/gm/carcontroller.py
@@ -1,10 +1,10 @@
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import interp
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import DT_CTRL, apply_driver_steer_torque_limits
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.gm import gmcan
 from openpilot.selfdrive.car.gm.values import DBC, CanBus, CarControllerParams, CruiseButtons
+from openpilot.selfdrive.car.helpers import interp
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 
 VisualAlert = car.CarControl.HUDControl.VisualAlert
diff --git a/selfdrive/car/gm/carstate.py b/selfdrive/car/gm/carstate.py
index a1129c59c8..97dbd389f4 100644
--- a/selfdrive/car/gm/carstate.py
+++ b/selfdrive/car/gm/carstate.py
@@ -1,9 +1,9 @@
 import copy
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import mean
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import mean
 from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.gm.values import DBC, AccState, CanBus, STEER_THRESHOLD
 
diff --git a/selfdrive/car/gm/interface.py b/selfdrive/car/gm/interface.py
index 1d4a6066cc..31b874502b 100755
--- a/selfdrive/car/gm/interface.py
+++ b/selfdrive/car/gm/interface.py
@@ -5,8 +5,8 @@ from math import fabs, exp
 from panda import Panda
 
 from openpilot.common.basedir import BASEDIR
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import create_button_events, get_safety_config, get_friction
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.gm.radar_interface import RADAR_HEADER_MSG
 from openpilot.selfdrive.car.gm.values import CAR, CruiseButtons, CarControllerParams, EV_CAR, CAMERA_ACC_CAR, CanBus
 from openpilot.selfdrive.car.interfaces import CarInterfaceBase, TorqueFromLateralAccelCallbackType, FRICTION_THRESHOLD, LatControlInputs, NanoFFModel
diff --git a/selfdrive/car/gm/radar_interface.py b/selfdrive/car/gm/radar_interface.py
index b893babd31..b305d418b8 100755
--- a/selfdrive/car/gm/radar_interface.py
+++ b/selfdrive/car/gm/radar_interface.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 import math
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.gm.values import DBC, CanBus
 from openpilot.selfdrive.car.interfaces import RadarInterfaceBase
 
diff --git a/selfdrive/car/helpers.py b/selfdrive/car/helpers.py
new file mode 100644
index 0000000000..81f6d6a6bc
--- /dev/null
+++ b/selfdrive/car/helpers.py
@@ -0,0 +1,22 @@
+def clip(x, lo, hi):
+  return max(lo, min(hi, x))
+
+
+def interp(x, xp, fp):
+  N = len(xp)
+
+  def get_interp(xv):
+    hi = 0
+    while hi < N and xv > xp[hi]:
+      hi += 1
+    low = hi - 1
+    return fp[-1] if hi == N and xv > xp[low] else (
+      fp[0] if hi == 0 else
+      (xv - xp[low]) * (fp[hi] - fp[low]) / (xp[hi] - xp[low]) + fp[low])
+
+  return [get_interp(v) for v in x] if hasattr(x, '__iter__') else get_interp(x)
+
+
+def mean(x):
+  return sum(x) / len(x)
+
diff --git a/selfdrive/car/honda/carcontroller.py b/selfdrive/car/honda/carcontroller.py
index 86815ae9f5..0f08ee21a8 100644
--- a/selfdrive/car/honda/carcontroller.py
+++ b/selfdrive/car/honda/carcontroller.py
@@ -1,9 +1,9 @@
 from collections import namedtuple
 
 from cereal import car
-from openpilot.common.numpy_fast import clip, interp
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import DT_CTRL, rate_limit, make_tester_present_msg
+from openpilot.selfdrive.car.helpers import clip, interp
 from openpilot.selfdrive.car.honda import hondacan
 from openpilot.selfdrive.car.honda.values import CruiseButtons, VISUAL_HUD, HONDA_BOSCH, HONDA_BOSCH_RADARLESS, HONDA_NIDEC_ALT_PCM_ACCEL, CarControllerParams
 from openpilot.selfdrive.car.interfaces import CarControllerBase
diff --git a/selfdrive/car/honda/carstate.py b/selfdrive/car/honda/carstate.py
index c98d1a72d3..956e6a3bd3 100644
--- a/selfdrive/car/honda/carstate.py
+++ b/selfdrive/car/honda/carstate.py
@@ -1,10 +1,10 @@
 from collections import defaultdict
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import interp
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import interp
 from openpilot.selfdrive.car.honda.hondacan import CanBus, get_cruise_speed_conversion
 from openpilot.selfdrive.car.honda.values import CAR, DBC, STEER_THRESHOLD, HONDA_BOSCH, \
                                                  HONDA_NIDEC_ALT_SCM_MESSAGES, HONDA_BOSCH_RADARLESS, \
diff --git a/selfdrive/car/honda/hondacan.py b/selfdrive/car/honda/hondacan.py
index 1be496d951..b350455014 100644
--- a/selfdrive/car/honda/hondacan.py
+++ b/selfdrive/car/honda/hondacan.py
@@ -1,5 +1,5 @@
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import CanBusBase
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.honda.values import HondaFlags, HONDA_BOSCH, HONDA_BOSCH_RADARLESS, CAR, CarControllerParams
 
 # CAN bus layout with relay
diff --git a/selfdrive/car/honda/interface.py b/selfdrive/car/honda/interface.py
index fdcba8bb81..4c9f9674d3 100755
--- a/selfdrive/car/honda/interface.py
+++ b/selfdrive/car/honda/interface.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 from cereal import car
 from panda import Panda
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import interp
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import interp
 from openpilot.selfdrive.car.honda.hondacan import CanBus
 from openpilot.selfdrive.car.honda.values import CarControllerParams, CruiseButtons, CruiseSettings, HondaFlags, CAR, HONDA_BOSCH, \
                                                  HONDA_NIDEC_ALT_SCM_MESSAGES, HONDA_BOSCH_RADARLESS
diff --git a/selfdrive/car/honda/values.py b/selfdrive/car/honda/values.py
index 5a78995c0a..53e5435f29 100644
--- a/selfdrive/car/honda/values.py
+++ b/selfdrive/car/honda/values.py
@@ -2,9 +2,9 @@ from dataclasses import dataclass
 from enum import Enum, IntFlag
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from panda.python import uds
 from openpilot.selfdrive.car import CarSpecs, PlatformConfig, Platforms, dbc_dict
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.docs_definitions import CarFootnote, CarHarness, CarDocs, CarParts, Column
 from openpilot.selfdrive.car.fw_query_definitions import FwQueryConfig, Request, StdQueries, p16
 
diff --git a/selfdrive/car/hyundai/carcontroller.py b/selfdrive/car/hyundai/carcontroller.py
index e6bc83283e..0e3a3f0afd 100644
--- a/selfdrive/car/hyundai/carcontroller.py
+++ b/selfdrive/car/hyundai/carcontroller.py
@@ -1,8 +1,8 @@
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import clip
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import DT_CTRL, apply_driver_steer_torque_limits, common_fault_avoidance, make_tester_present_msg
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.hyundai import hyundaicanfd, hyundaican
 from openpilot.selfdrive.car.hyundai.hyundaicanfd import CanBus
 from openpilot.selfdrive.car.hyundai.values import HyundaiFlags, Buttons, CarControllerParams, CANFD_CAR, CAR
diff --git a/selfdrive/car/hyundai/carstate.py b/selfdrive/car/hyundai/carstate.py
index 41cb9ee457..1b56b3304e 100644
--- a/selfdrive/car/hyundai/carstate.py
+++ b/selfdrive/car/hyundai/carstate.py
@@ -3,9 +3,9 @@ import copy
 import math
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from opendbc.can.parser import CANParser
 from opendbc.can.can_define import CANDefine
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.hyundai.hyundaicanfd import CanBus
 from openpilot.selfdrive.car.hyundai.values import HyundaiFlags, CAR, DBC, CAN_GEARS, CAMERA_SCC_CAR, \
                                                    CANFD_CAR, Buttons, CarControllerParams
diff --git a/selfdrive/car/hyundai/hyundaicanfd.py b/selfdrive/car/hyundai/hyundaicanfd.py
index 54804f94fd..bd46f18612 100644
--- a/selfdrive/car/hyundai/hyundaicanfd.py
+++ b/selfdrive/car/hyundai/hyundaicanfd.py
@@ -1,5 +1,5 @@
-from openpilot.common.numpy_fast import clip
 from openpilot.selfdrive.car import CanBusBase
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.hyundai.values import HyundaiFlags
 
 
diff --git a/selfdrive/car/hyundai/values.py b/selfdrive/car/hyundai/values.py
index 8ed0edd319..0db82a7577 100644
--- a/selfdrive/car/hyundai/values.py
+++ b/selfdrive/car/hyundai/values.py
@@ -4,8 +4,8 @@ from enum import Enum, IntFlag
 
 from cereal import car
 from panda.python import uds
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import CarSpecs, DbcDict, PlatformConfig, Platforms, dbc_dict
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.docs_definitions import CarFootnote, CarHarness, CarDocs, CarParts, Column
 from openpilot.selfdrive.car.fw_query_definitions import FwQueryConfig, Request, p16
 
diff --git a/selfdrive/car/interfaces.py b/selfdrive/car/interfaces.py
index fcdc3d77fe..90d50f0903 100644
--- a/selfdrive/car/interfaces.py
+++ b/selfdrive/car/interfaces.py
@@ -10,10 +10,10 @@ from functools import cache
 
 from cereal import car
 from openpilot.common.basedir import BASEDIR
-from openpilot.common.conversions import Conversions as CV
 from openpilot.common.simple_kalman import KF1D, get_kalman_gain
-from openpilot.common.numpy_fast import clip
 from openpilot.selfdrive.car import DT_CTRL, apply_hysteresis, gen_empty_fingerprint, scale_rot_inertia, scale_tire_stiffness, get_friction, STD_CARGO_KG
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.values import PLATFORMS
 from openpilot.selfdrive.controls.lib.events import Events
 from openpilot.selfdrive.pandad import can_capnp_to_list
diff --git a/selfdrive/car/mazda/carstate.py b/selfdrive/car/mazda/carstate.py
index 83b238fb68..83aa09b66b 100644
--- a/selfdrive/car/mazda/carstate.py
+++ b/selfdrive/car/mazda/carstate.py
@@ -1,7 +1,7 @@
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.mazda.values import DBC, LKAS_LIMITS, MazdaFlags
 
diff --git a/selfdrive/car/mazda/interface.py b/selfdrive/car/mazda/interface.py
index 6992d49ffe..fcec6b18b0 100755
--- a/selfdrive/car/mazda/interface.py
+++ b/selfdrive/car/mazda/interface.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.selfdrive.car.mazda.values import CAR, LKAS_LIMITS
 from openpilot.selfdrive.car import create_button_events, get_safety_config
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.mazda.values import CAR, LKAS_LIMITS
 from openpilot.selfdrive.car.interfaces import CarInterfaceBase
 
 ButtonType = car.CarState.ButtonEvent.Type
diff --git a/selfdrive/car/mazda/values.py b/selfdrive/car/mazda/values.py
index a8c808d582..cfd7067db6 100644
--- a/selfdrive/car/mazda/values.py
+++ b/selfdrive/car/mazda/values.py
@@ -2,8 +2,8 @@ from dataclasses import dataclass, field
 from enum import IntFlag
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import CarSpecs, DbcDict, PlatformConfig, Platforms, dbc_dict
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.docs_definitions import CarHarness, CarDocs, CarParts
 from openpilot.selfdrive.car.fw_query_definitions import FwQueryConfig, Request, StdQueries
 
diff --git a/selfdrive/car/nissan/carstate.py b/selfdrive/car/nissan/carstate.py
index 57146b49c4..c38173c3e3 100644
--- a/selfdrive/car/nissan/carstate.py
+++ b/selfdrive/car/nissan/carstate.py
@@ -2,9 +2,9 @@ import copy
 from collections import deque
 from cereal import car
 from opendbc.can.can_define import CANDefine
-from openpilot.selfdrive.car.interfaces import CarStateBase
-from openpilot.common.conversions import Conversions as CV
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.nissan.values import CAR, DBC, CarControllerParams
 
 TORQUE_SAMPLES = 12
diff --git a/selfdrive/car/subaru/carcontroller.py b/selfdrive/car/subaru/carcontroller.py
index acabc2ca5a..c8c2e7417b 100644
--- a/selfdrive/car/subaru/carcontroller.py
+++ b/selfdrive/car/subaru/carcontroller.py
@@ -1,6 +1,6 @@
-from openpilot.common.numpy_fast import clip, interp
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import apply_driver_steer_torque_limits, common_fault_avoidance, make_tester_present_msg
+from openpilot.selfdrive.car.helpers import clip, interp
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 from openpilot.selfdrive.car.subaru import subarucan
 from openpilot.selfdrive.car.subaru.values import DBC, GLOBAL_ES_ADDR, CanBus, CarControllerParams, SubaruFlags
diff --git a/selfdrive/car/subaru/carstate.py b/selfdrive/car/subaru/carstate.py
index 821ff2c151..0501494fdd 100644
--- a/selfdrive/car/subaru/carstate.py
+++ b/selfdrive/car/subaru/carstate.py
@@ -1,9 +1,9 @@
 import copy
 from cereal import car
 from opendbc.can.can_define import CANDefine
-from openpilot.common.conversions import Conversions as CV
-from openpilot.selfdrive.car.interfaces import CarStateBase
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.subaru.values import DBC, CanBus, SubaruFlags
 from openpilot.selfdrive.car import CanSignalRateCalculator
 
diff --git a/selfdrive/car/tesla/carcontroller.py b/selfdrive/car/tesla/carcontroller.py
index 32d83dfb68..ed81fd0c50 100644
--- a/selfdrive/car/tesla/carcontroller.py
+++ b/selfdrive/car/tesla/carcontroller.py
@@ -1,6 +1,6 @@
-from openpilot.common.numpy_fast import clip
 from opendbc.can.packer import CANPacker
 from openpilot.selfdrive.car import apply_std_steer_angle_limits
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 from openpilot.selfdrive.car.tesla.teslacan import TeslaCAN
 from openpilot.selfdrive.car.tesla.values import DBC, CANBUS, CarControllerParams
diff --git a/selfdrive/car/tesla/carstate.py b/selfdrive/car/tesla/carstate.py
index 645ea46014..5aa21cbc7c 100644
--- a/selfdrive/car/tesla/carstate.py
+++ b/selfdrive/car/tesla/carstate.py
@@ -1,11 +1,11 @@
 import copy
 from collections import deque
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.selfdrive.car.tesla.values import CAR, DBC, CANBUS, GEAR_MAP, DOORS, BUTTONS
-from openpilot.selfdrive.car.interfaces import CarStateBase
 from opendbc.can.parser import CANParser
 from opendbc.can.can_define import CANDefine
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.tesla.values import CAR, DBC, CANBUS, GEAR_MAP, DOORS, BUTTONS
+from openpilot.selfdrive.car.interfaces import CarStateBase
 
 class CarState(CarStateBase):
   def __init__(self, CP):
diff --git a/selfdrive/car/tesla/teslacan.py b/selfdrive/car/tesla/teslacan.py
index f8cd138e77..22e0ac6c4e 100644
--- a/selfdrive/car/tesla/teslacan.py
+++ b/selfdrive/car/tesla/teslacan.py
@@ -1,6 +1,6 @@
 import crcmod
 
-from openpilot.common.conversions import Conversions as CV
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.tesla.values import CANBUS, CarControllerParams
 
 
diff --git a/selfdrive/car/toyota/carcontroller.py b/selfdrive/car/toyota/carcontroller.py
index f33f8673ea..ea49a49026 100644
--- a/selfdrive/car/toyota/carcontroller.py
+++ b/selfdrive/car/toyota/carcontroller.py
@@ -1,6 +1,6 @@
 from cereal import car
-from openpilot.common.numpy_fast import clip
 from openpilot.selfdrive.car import apply_meas_steer_torque_limits, apply_std_steer_angle_limits, common_fault_avoidance, make_can_msg, make_tester_present_msg
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 from openpilot.selfdrive.car.toyota import toyotacan
 from openpilot.selfdrive.car.toyota.values import CAR, STATIC_DSU_MSGS, NO_STOP_TIMER_CAR, TSS2_CAR, \
diff --git a/selfdrive/car/toyota/carstate.py b/selfdrive/car/toyota/carstate.py
index e02293da4e..6037585c90 100644
--- a/selfdrive/car/toyota/carstate.py
+++ b/selfdrive/car/toyota/carstate.py
@@ -1,12 +1,12 @@
 import copy
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.common.numpy_fast import mean
-from openpilot.common.filter_simple import FirstOrderFilter
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
 from openpilot.selfdrive.car import DT_CTRL
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.filter_simple import FirstOrderFilter
+from openpilot.selfdrive.car.helpers import mean
 from openpilot.selfdrive.car.interfaces import CarStateBase
 from openpilot.selfdrive.car.toyota.values import ToyotaFlags, CAR, DBC, STEER_THRESHOLD, NO_STOP_TIMER_CAR, \
                                                   TSS2_CAR, RADAR_ACC_CAR, EPS_SCALE, UNSUPPORTED_DSU_CAR
diff --git a/selfdrive/car/toyota/values.py b/selfdrive/car/toyota/values.py
index 8022e8b3ab..ca422c73ef 100644
--- a/selfdrive/car/toyota/values.py
+++ b/selfdrive/car/toyota/values.py
@@ -4,9 +4,8 @@ from dataclasses import dataclass, field
 from enum import Enum, IntFlag
 
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.selfdrive.car import CarSpecs, PlatformConfig, Platforms
-from openpilot.selfdrive.car import AngleRateLimit, dbc_dict
+from openpilot.selfdrive.car import CarSpecs, PlatformConfig, Platforms, AngleRateLimit, dbc_dict
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.docs_definitions import CarFootnote, CarDocs, Column, CarParts, CarHarness
 from openpilot.selfdrive.car.fw_query_definitions import FwQueryConfig, Request, StdQueries
 
diff --git a/selfdrive/car/volkswagen/carcontroller.py b/selfdrive/car/volkswagen/carcontroller.py
index dda8de6cab..4f8552b16a 100644
--- a/selfdrive/car/volkswagen/carcontroller.py
+++ b/selfdrive/car/volkswagen/carcontroller.py
@@ -1,8 +1,8 @@
 from cereal import car
 from opendbc.can.packer import CANPacker
-from openpilot.common.numpy_fast import clip
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import DT_CTRL, apply_driver_steer_torque_limits
+from openpilot.selfdrive.car.conversions import Conversions as CV
+from openpilot.selfdrive.car.helpers import clip
 from openpilot.selfdrive.car.interfaces import CarControllerBase
 from openpilot.selfdrive.car.volkswagen import mqbcan, pqcan
 from openpilot.selfdrive.car.volkswagen.values import CANBUS, CarControllerParams, VolkswagenFlags
diff --git a/selfdrive/car/volkswagen/carstate.py b/selfdrive/car/volkswagen/carstate.py
index ec6403496f..c53639a7dd 100644
--- a/selfdrive/car/volkswagen/carstate.py
+++ b/selfdrive/car/volkswagen/carstate.py
@@ -1,8 +1,8 @@
 import numpy as np
 from cereal import car
-from openpilot.common.conversions import Conversions as CV
-from openpilot.selfdrive.car.interfaces import CarStateBase
 from opendbc.can.parser import CANParser
+from openpilot.selfdrive.car.interfaces import CarStateBase
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.volkswagen.values import DBC, CANBUS, NetworkLocation, TransmissionType, GearShifter, \
                                             CarControllerParams, VolkswagenFlags
 
diff --git a/selfdrive/car/volkswagen/values.py b/selfdrive/car/volkswagen/values.py
index 69dd63fefd..27816712f6 100644
--- a/selfdrive/car/volkswagen/values.py
+++ b/selfdrive/car/volkswagen/values.py
@@ -5,8 +5,8 @@ from enum import Enum, IntFlag, StrEnum
 from cereal import car
 from panda.python import uds
 from opendbc.can.can_define import CANDefine
-from openpilot.common.conversions import Conversions as CV
 from openpilot.selfdrive.car import dbc_dict, CarSpecs, DbcDict, PlatformConfig, Platforms
+from openpilot.selfdrive.car.conversions import Conversions as CV
 from openpilot.selfdrive.car.docs_definitions import CarFootnote, CarHarness, CarDocs, CarParts, Column, \
                                                      Device
 from openpilot.selfdrive.car.fw_query_definitions import EcuAddrSubAddr, FwQueryConfig, Request, p16