diff --git a/selfdrive/car/__init__.py b/selfdrive/car/__init__.py
index a34452e5ca..5f806ee2ff 100644
--- a/selfdrive/car/__init__.py
+++ b/selfdrive/car/__init__.py
@@ -9,8 +9,8 @@ import capnp
 
 from cereal import car
 from panda.python.uds import SERVICE_TYPE
-from openpilot.selfdrive.car.can_definitions import CanData
 from openpilot.selfdrive.car import structs
+from openpilot.selfdrive.car.can_definitions import CanData
 from openpilot.selfdrive.car.docs_definitions import CarDocs
 from openpilot.selfdrive.car.helpers import clip, interp
 
diff --git a/selfdrive/car/ford/carstate.py b/selfdrive/car/ford/carstate.py
index 64d7e4e782..14c3174163 100644
--- a/selfdrive/car/ford/carstate.py
+++ b/selfdrive/car/ford/carstate.py
@@ -1,7 +1,7 @@
 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 import structs
+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/interfaces.py b/selfdrive/car/interfaces.py
index 2d40b86f84..00333aac14 100644
--- a/selfdrive/car/interfaces.py
+++ b/selfdrive/car/interfaces.py
@@ -101,7 +101,7 @@ class CarInterfaceBase(ABC):
 
     # TODO: this
     # self.CS: CarStateBase = CarState(CP)
-    self.CS = CarState(CP)
+    self.CS: CarStateBase = CarState(CP)
     self.cp = self.CS.get_can_parser(CP)
     self.cp_cam = self.CS.get_cam_can_parser(CP)
     self.cp_adas = self.CS.get_adas_can_parser(CP)
@@ -385,10 +385,9 @@ class CarStateBase(ABC):
     K = get_kalman_gain(DT_CTRL, np.array(A), np.array(C), np.array(Q), R)
     self.v_ego_kf = KF1D(x0=x0, A=A, C=C[0], K=K)
 
-  # TODO: this
-  # @abstractmethod
-  # def update(self, *args) -> structs.CarState:
-  #   raise NotImplementedError
+  @abstractmethod
+  def update(self, *args) -> structs.CarState:
+    pass
 
   def update_speed_kf(self, v_ego_raw):
     if abs(v_ego_raw - self.v_ego_kf.x[0][0]) > 2.0:  # Prevent large accelerations when car starts at non zero speed
diff --git a/selfdrive/car/toyota/carstate.py b/selfdrive/car/toyota/carstate.py
index b6f16e96be..6088f89f30 100644
--- a/selfdrive/car/toyota/carstate.py
+++ b/selfdrive/car/toyota/carstate.py
@@ -2,9 +2,8 @@ import copy
 
 from opendbc.can.can_define import CANDefine
 from opendbc.can.parser import CANParser
-from openpilot.selfdrive.car import DT_CTRL
+from openpilot.selfdrive.car import DT_CTRL, structs
 from openpilot.selfdrive.car.conversions import Conversions as CV
-from openpilot.selfdrive.car import structs
 from openpilot.selfdrive.car.filter_simple import FirstOrderFilter
 from openpilot.selfdrive.car.helpers import mean
 from openpilot.selfdrive.car.interfaces import CarStateBase
diff --git a/selfdrive/car/toyota/interface.py b/selfdrive/car/toyota/interface.py
index c7c6fe0da1..58778c7b97 100644
--- a/selfdrive/car/toyota/interface.py
+++ b/selfdrive/car/toyota/interface.py
@@ -1,10 +1,10 @@
 from cereal import car
 from panda import Panda
 from panda.python import uds
+from openpilot.selfdrive.car.toyota.carstate import CarState
 from openpilot.selfdrive.car.toyota.values import Ecu, CAR, DBC, ToyotaFlags, CarControllerParams, TSS2_CAR, RADAR_ACC_CAR, NO_DSU_CAR, \
                                         MIN_ACC_SPEED, EPS_SCALE, UNSUPPORTED_DSU_CAR, NO_STOP_TIMER_CAR, ANGLE_CONTROL_CAR
-from openpilot.selfdrive.car import create_button_events, get_safety_config
-from openpilot.selfdrive.car import structs
+from openpilot.selfdrive.car import create_button_events, get_safety_config, structs
 from openpilot.selfdrive.car.disable_ecu import disable_ecu
 from openpilot.selfdrive.car.interfaces import CarInterfaceBase
 
@@ -14,6 +14,8 @@ SteerControlType = structs.CarParams.SteerControlType
 
 
 class CarInterface(CarInterfaceBase):
+  CS: CarState
+
   @staticmethod
   def get_pid_accel_limits(CP, current_speed, cruise_speed):
     return CarControllerParams.ACCEL_MIN, CarControllerParams.ACCEL_MAX