Troubleshooting

From UnityCar Wiki

Wheels sinking into terrain

Most of the time this problem is caused by the fact that car's GameObject layer and terrain layer are the same. To fix this, just change car's GameObject layer using any other layer (expect of course Ignore Raycast) or even better add a new one.

Wheels shaking vertically or strange car behavior

Most of the time this problem is caused by the fact that car's GameObject layer and collider's GameObject layer are NOT the same. To fix this, just set car's GameObject layer and collider's GameObject layer to the same layer.