bypass HDA2 dashcam with file (#24803)

Co-authored-by: Comma Device <device@comma.ai>

selfdrive/car/hyundai/interface.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+import os
 from cereal import car
 from panda import Panda
 from common.conversions import Conversions as CV
@@ -37,7 +38,9 @@ class CarInterface(CarInterfaceBase):
     # These cars have been put into dashcam only due to both a lack of users and test coverage.
     # These cars likely still work fine. Once a user confirms each car works and a test route is
     # added to selfdrive/car/tests/routes.py, we can remove it from this list.
-    ret.dashcamOnly = candidate in {CAR.KIA_OPTIMA_H, CAR.ELANTRA_GT_I30} or candidate in HDA2_CAR
+    ret.dashcamOnly = candidate in {CAR.KIA_OPTIMA_H, CAR.ELANTRA_GT_I30}
+    if candidate in HDA2_CAR:
+      ret.dashcamOnly = not os.path.exists('/data/enable-ev6')
 
     ret.steerActuatorDelay = 0.1  # Default delay
     ret.steerRateCost = 0.5