I´m developing my own custom collision system, along with the racing physics.

In my case, I have a invisible animated mesh, that matchs exactly with the car model, and follows the car chassis orientation during its rotations, relative to the movement direction. Evaluating this two variables and some few other I can solve the collision behaviour. Its not easy, but its progressing

But this is only a solution I found, I think all depends of what one are tryong to achieve.