[QUICK HELP] Collision Acting weird

When my car hits something, it goes haywire and spins all around. All it has is the mesh components, a box collider and a rigidbody. I want the red car to move, just not so easily. It literally grows wings and flies. Also, I don’t know why it can go through the walls. They have box colliders!
The following is a video of what happens: - YouTube
The second time I pressed play, I never touched anything.

It’s hard to diagnose by looking at a video and reading description. Physics problems are always tricky. Here’s a general rule of thumb: Scale matters. And I noticed you have a loooooong ass tunnel there. For testing purposes, see if you can break physics in a small tunnel, one that doesn’t exceed the dimensions of the cars by too much. If the car is 1 unit of length, make the tunnel 10 units. Then ram the walls and all that stuff. Then you increase the tunnel a little more and repeat the experiment. If it does get worse with the size you probably need to rethink how you are making this tunnel. I suggest making it several sections connected together, so that way the objects are never colliding with absurdly larger colliders.

I don’t like writing ‘answers’ that are not definitive but just suggest something to do, but as I said physics bugs are tricky. You could also experiment with collision type on your rigidbodies.

It could be the mass of the car’s not being enough, sometimes this can have weird affects on the physics which is what you are seeing. Also the gravity could be causing issues here.

Have you tried setting the car mass higher to see if there is a difference?