PhysXVehicle(v. 3.2.2) wierd behaviour on overlapping surfaces.

Visualization of problem:

Our artists sometimes cheat when it comes to build our collision world and we get overlapping surfaces.
When you drive above these the vehicle start to behave wierd.

So I’m just curious about what’s really happening? If someone could explain it I would be very grateful.

The raycast should lways returns the first hit along the raycast direction. The vehicle then simply reacts to the result of the raycast.

What sort of weirdnesses are you getting? Do you have normals pointing downwards that the car could be driving on?