diff --git a/selfdrive/car/data_structures.py b/selfdrive/car/data_structures.py
index ea4fa44dc7..ddc182ef50 100644
--- a/selfdrive/car/data_structures.py
+++ b/selfdrive/car/data_structures.py
@@ -1,7 +1,8 @@
-from dataclasses import dataclass, fields, is_dataclass
+from dataclasses import dataclass, fields, field, is_dataclass
 from enum import Enum, StrEnum as _StrEnum, auto
 # from typing import Type, TypeVar
-from typing import Type, TypeVar, TYPE_CHECKING, Any, get_type_hints, get_origin
+from typing import TypeVar, TYPE_CHECKING, Any, get_type_hints, get_origin
+from selfdrive.car.data_test_kinda_works_chatgpt import auto_field, apply_auto_fields
 
 if TYPE_CHECKING:
     from _typeshed import DataclassInstance
@@ -10,6 +11,8 @@ if TYPE_CHECKING:
 #
 # T = TypeVar('T', bound='Struct')
 
+_FIELDS = '__dataclass_fields__'
+
 
 class StrEnum(_StrEnum):
   @staticmethod
@@ -30,35 +33,35 @@ class StrEnum(_StrEnum):
 T = TypeVar('T', bound='DataclassInstance')
 
 
-class Struct:
-  @classmethod
-  def new_message(cls: Type[T], **kwargs: Any) -> T:
-    if not is_dataclass(cls):
-      raise TypeError(f"{cls.__name__} is not a dataclass")
-
-    init_values = {}
-    type_hints = get_type_hints(cls)
-    print(type_hints)
-    for f in fields(cls):
-      field_type = type_hints[f.name]
-      print(f.name, f.type, field_type)
-      print(issubclass(field_type, Enum))
-      if issubclass(field_type, Enum):
-        init_values[f.name] = kwargs.get(f.name, list(field_type)[0])
-        # TODO: fix this
-        # assert issubclass(init_values[f.name], type(field_type)), f"Expected {field_type} for {f.name}, got {type(init_values[f.name])}"
-      else:
-        # FIXME: typing check hack since mypy doesn't catch anything
-        init_values[f.name] = kwargs.get(f.name, field_type())
-        print('field_type', field_type, f.type)
-        # TODO: this is so bad
-        assert isinstance(init_values[f.name], get_origin(f.type) or f.type), f"Expected {field_type} for {f.name}, got {type(init_values[f.name])}"
-
-    return cls(**init_values)
+# class Struct:
+#   @classmethod
+#   def new_message(cls: type[T], **kwargs: Any) -> T:
+#     if not is_dataclass(cls):
+#       raise TypeError(f"{cls.__name__} is not a dataclass")
+#
+#     init_values = {}
+#     type_hints = get_type_hints(cls)
+#     print(type_hints)
+#     for f in fields(cls):
+#       field_type = type_hints[f.name]
+#       print(f.name, f.type, field_type)
+#       print(issubclass(field_type, Enum))
+#       if issubclass(field_type, Enum):
+#         init_values[f.name] = kwargs.get(f.name, list(field_type)[0])
+#         # TODO: fix this
+#         # assert issubclass(init_values[f.name], type(field_type)), f"Expected {field_type} for {f.name}, got {type(init_values[f.name])}"
+#       else:
+#         # FIXME: typing check hack since mypy doesn't catch anything
+#         init_values[f.name] = kwargs.get(f.name, field_type())
+#         print('field_type', field_type, f.type)
+#         # TODO: this is so bad
+#         assert isinstance(init_values[f.name], get_origin(f.type) or f.type), f"Expected {field_type} for {f.name}, got {type(init_values[f.name])}"
+#
+#     return cls(**init_values)
 
 
 @dataclass
-class RadarData(Struct):
+class RadarData:
   errors: list['Error']
   points: list['RadarPoint']
 
@@ -68,7 +71,7 @@ class RadarData(Struct):
     wrongConfig = auto()
 
   @dataclass
-  class RadarPoint(Struct):
+  class RadarPoint:
     trackId: int  # no trackId reuse
 
     # these 3 are the minimum required
@@ -85,31 +88,33 @@ class RadarData(Struct):
 
 
 @dataclass
-class CarParams(Struct):
-  carName: str
-  carFingerprint: str
-  fuzzyFingerprint: bool
+@apply_auto_fields
+class CarParams:
+  carName: str = auto_field()
+  carFingerprint: str = auto_field()
+  fuzzyFingerprint: bool = auto_field()
 
-  notCar: bool  # flag for non-car robotics platforms
+  notCar: bool = auto_field()  # flag for non-car robotics platforms
 
-  carFw: list['CarFw']
+  carFw: list['CarParams.CarFw'] = auto_field()
 
   class SteerControlType(StrEnum):
     torque = auto()
     angle = auto()
 
   @dataclass
-  class CarFw(Struct):
-    ecu: 'CarParams.Ecu'
-    fwVersion: bytes
-    address: int
-    subAddress: int
-    responseAddress: int
-    request: list[bytes]
-    brand: str
-    bus: int
-    logging: bool
-    obdMultiplexing: bool
+  @apply_auto_fields
+  class CarFw:
+    ecu: 'CarParams.Ecu' = field(default_factory=lambda: CarParams.Ecu.unknown)
+    fwVersion: bytes = auto_field()
+    address: int = auto_field()
+    subAddress: int = auto_field()
+    responseAddress: int = auto_field()
+    request: list[bytes] = auto_field()
+    brand: str = auto_field()
+    bus: int = auto_field()
+    logging: bool = auto_field()
+    obdMultiplexing: bool = auto_field()
 
   class Ecu(StrEnum):
     eps = auto()
@@ -144,10 +149,88 @@ class CarParams(Struct):
     debug = auto()
 
 
-# CP: CarParams = CarParams.new_message(carName='toyota', fuzzyFingerprint=123)
-# CP: CarParams = CarParams(carName='toyota', fuzzyFingerprint=123)
+# # CP: CarParams = CarParams.new_message(carName='toyota', fuzzyFingerprint=123)
+# # CP: CarParams = CarParams(carName='toyota', fuzzyFingerprint=123)
+#
+# # import ast
+#
+#
+# # test = ast.literal_eval('CarParams.CarFw')
+#
+# def mywrapper(cls):
+#
+#   cls_annotations = cls.__dict__.get('__annotations__', {})
+#   fields = {}
+#   for name, _type in cls_annotations.items():
+#     f = field(default_factory=_type)
+#     setattr(cls, name, f)
+#     fields[name] = f
+#
+#   setattr(cls, _FIELDS, fields)
+#
+#   print('cls_annotations', cls_annotations)
+#   # cls.hi = 123
+#
+#   return cls
+#
+#
+# # def mywrapper2(cls):
+# #   class Test:
+# #     pass
+# #   return Test
+#
+#
+# @dataclass
+# class CarControl1:
+#   enabled: bool
+#
+# @dataclass
+# class CarControl2:
+#   enabled: bool = field(default_factory=bool)
+#
+#
+# # @mywrapper2
+# @dataclass()
+# @mywrapper
+# class CarControl:
+#   # enabled: bool = field(default_factory=bool)
+#   enabled: bool = None
+#   pts: list[int] = None
+#   logMonoTime: int = None
+#
+#
+# CC = CarControl()
+
 
-import ast
+@dataclass
+@apply_auto_fields
+class CarControl:
+  enabled: bool = auto_field()
+  pts: list[int] = auto_field()
+  logMonoTime: int = auto_field()
+  test: None = auto_field()
 
 
-# test = ast.literal_eval('CarParams.CarFw')
+# testing: if origin_typ in (int, float, str, bytes, list, tuple, set, dict, bool):
+@dataclass
+@apply_auto_fields
+class Test997:
+  a: int = auto_field()
+  b: float = auto_field()
+  c: str = auto_field()
+  d: bytes = auto_field()
+  e: list[int] = auto_field()
+  f: tuple[int] = auto_field()
+  g: set[int] = auto_field()
+  h: dict[str, int] = auto_field()
+  i: bool = auto_field()
+  ecu: CarParams.Ecu = auto_field()
+  carFw: CarParams.CarFw = auto_field()
+
+# Out[4]: Test997(a=0, b=0.0, c='', d=b'', e=[], f=(), g=set(), h={}, i=False)
+
+CarControl()
+
+CP = CarParams()
+CP.carFw = [CarParams.CarFw()]
+CP.carFw = [CarParams.Ecu.eps]