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.

It's getting better and better! The only flaws i've noticed:
-the driver's neck looks a bit thin to me
-the shadow sprite doesn't match the car
-i see the pixelated borders on the trees, looks like you use overlay flag.I advise you to use tga or dds sprites with alpha channel instead
Good luck with you game