Like I said in another thread, I think the damage would look a lot better if all the parts of the cars, weren't connected to each other. This would mean more of the engine bay and trunk would need modelling, because if the bumper would get smashed, part of the engine, or car skeleton would become visible, and if we get that effect, that parts can damage seperatly (what it doesn't seem to do now), it wouldn't be too far away from having parts actually fall off.
I went to the BelCar races yesterday, and in the sprint cup a toyota yaris (Vitz??) went into the barriers, the bumper fell off, the wheel was totally busted, and the hood was smashed a bit. In lfs it would more likely be, damage to the wheels (that's good), but the hood would be bent in relation to the bumper, wich doesn't look right, because mostly the hood isn't made of the same material as a bumper, so it should act differently. If it acted differently, I think it would be still a temporary solution, but it would look much better.