diff --git a/selfdrive/car/__init__.py b/selfdrive/car/__init__.py
index 75b85cab2f..3b749101c9 100644
--- a/selfdrive/car/__init__.py
+++ b/selfdrive/car/__init__.py
@@ -246,7 +246,7 @@ class CanSignalRateCalculator:
 CarInfos = CarInfo | list[CarInfo]
 
 
-@dataclass(kw_only=True)
+@dataclass(frozen=True, kw_only=True)
 class CarSpecs:
   mass: float
   wheelbase: float
@@ -256,7 +256,7 @@ class CarSpecs:
   minEnableSpeed: float = field(default=-1.)
 
 
-@dataclass(order=True)
+@dataclass(frozen=True, order=True)
 class PlatformConfig:
   platform_str: str
   car_info: CarInfos
diff --git a/selfdrive/car/ford/values.py b/selfdrive/car/ford/values.py
index ef99cf5f34..caa3eb0d37 100644
--- a/selfdrive/car/ford/values.py
+++ b/selfdrive/car/ford/values.py
@@ -63,7 +63,7 @@ class FordCarInfo(CarInfo):
       self.car_parts = CarParts([Device.threex, harness])
 
 
-@dataclass
+@dataclass(frozen=True)
 class FordPlatformConfig(PlatformConfig):
   dbc_dict: DbcDict = field(default_factory=lambda: dbc_dict('ford_lincoln_base_pt', RADAR.DELPHI_MRR))
 
diff --git a/selfdrive/car/gm/values.py b/selfdrive/car/gm/values.py
index 53dbde87f4..35fdf3fb92 100644
--- a/selfdrive/car/gm/values.py
+++ b/selfdrive/car/gm/values.py
@@ -79,7 +79,7 @@ class GMCarInfo(CarInfo):
       self.footnotes.append(Footnote.OBD_II)
 
 
-@dataclass
+@dataclass(frozen=True)
 class GMPlatformConfig(PlatformConfig):
   dbc_dict: DbcDict = field(default_factory=lambda: dbc_dict('gm_global_a_powertrain_generated', 'gm_global_a_object', chassis_dbc='gm_global_a_chassis'))
 
diff --git a/selfdrive/car/subaru/values.py b/selfdrive/car/subaru/values.py
index 0fd7ab9c13..a296550b12 100644
--- a/selfdrive/car/subaru/values.py
+++ b/selfdrive/car/subaru/values.py
@@ -89,7 +89,7 @@ class SubaruCarInfo(CarInfo):
       self.footnotes.append(Footnote.EXP_LONG)
 
 
-@dataclass
+@dataclass(frozen=True)
 class SubaruPlatformConfig(PlatformConfig):
   dbc_dict: DbcDict = field(default_factory=lambda: dbc_dict('subaru_global_2017_generated', None))
 
diff --git a/selfdrive/car/volkswagen/values.py b/selfdrive/car/volkswagen/values.py
index f029740284..4dff9205d6 100644
--- a/selfdrive/car/volkswagen/values.py
+++ b/selfdrive/car/volkswagen/values.py
@@ -112,15 +112,15 @@ class CANBUS:
 class VolkswagenFlags(IntFlag):
   STOCK_HCA_PRESENT = 1
 
-@dataclass
+@dataclass(frozen=True)
 class VolkswagenMQBPlatformConfig(PlatformConfig):
   dbc_dict: DbcDict = field(default_factory=lambda: dbc_dict('vw_mqb_2010', None))
 
-@dataclass
+@dataclass(frozen=True)
 class VolkswagenPQPlatformConfig(PlatformConfig):
   dbc_dict: DbcDict = field(default_factory=lambda: dbc_dict('vw_golf_mk4', None))
 
-@dataclass(kw_only=True)
+@dataclass(frozen=True, kw_only=True)
 class VolkswagenCarSpecs(CarSpecs):
   steerRatio: float = field(default=15.6)