Im interested on that too, on some collisions car looks like paper/low mass.
And in my case restitution bounce is set to 0, etc… to avoid the car behaviour feel like a pinball.
Used in FGearCustomCollision and materials/objects, tried lots of variations, but still.
@lazybitgames Im doing some research, is all about this?:
Any other doc related that we should know for that?
Also it seems there are problems with CCD no idea if already fixed in 5.7.1:
I guess some new options in the PM for contact modifications will be great to test.