Unity crashing on collision and editing wheel collider properties

Hi, I have created a test terrain for vehicles to use in a game, but whenever the car lands anywhere but the bottom it force closes with no warning, I’ve tried all the things I could to fix it, but was unable to do so. What are my options?
Also, how would I edit a wheel collider to add a bounce to it.

I don’t want to sacrifice the mesh collider for a box collider as that will cause more issues for me in the future

Hello guys
I have a sample problem when I build car racing games before.
I dont know what is a correct reason but it fixed when I make mesh size bigger in mesh import options. If you dont have good result then please ping me
I will refer second method.