Vehicle physics can be improved easily. I have some ideas that could easily fix them.
1. Vehicles can constantly send raycasts and detect any nearby bricks, players, and vehicles. If any of those entities are detected, it will prepare to play a crash animation. All a crash animation will do is, when the vehicle smashes into an entity, it will play a sound and the vehicle will spawn some oil emitters for 2 seconds, and then they will go away.
2. All vehicles are actually mountable bots, that can climb hills, and play animations as they are moving, like wheels moving, turning, all of that stuff.
Hopefully someone will actually make this happen! C: