Stuck on vehicle creation

Its a tad smaller than the shootergame guy(to his waist), but not so much that i’d imagine it would screw with physics, could be units maybe, but my 3dsmax settings are centimeters, which is correct right?
If i set all the physics bodies to default, the car falls onto the surface then rolls around as if the wheels are spheres, and if i set the wheels to kinematic, it bounces away.