As cars take on damage, the cars change in appearance. At a certain damage level, the hood pops up and later flies off. The odd thing is that with the hood popped up, the outside view makes it look like you wouldn't be able to see out the front window. But using the in-car view, your view is unobstructed. Taking on more damage, cars eventually start to smoke and flames come from the engine.
Cars crumple, stuff flies off, things burn.
Good old destruction. The game offers several views, but probably the best for driving is the in-car view. Unfortunately, the in-car view has a problem. Cars can go airborne, and if one does and lands in front of you, the car is there, and then it isn't. It disappears all of a sudden due to some clipping problems.