Not for me. I hope you understand that I don't have the possibility to individually help all users with their projects.

I can just advise that physics vehicles require a certain smoothness of the surface, and won't drive well on raw triangles. Use terrain for the ground. Also look in the manual about adjusting the car and suspension parameters. If you want to make your own car, you might get much more help on the nVidia PhysX forum - that was at least very helpful for me.