Well.. for example...
A Formula1 car is built out of carbon fibers.. meaning that soilers don't get wrinkled when they smack something at 300+kmh!
I think the damage realism would be even better if certain body parts of a car could break off...
EG: front and rear bumpers, wheels, spoilers.
This would also give us a more realist situation of having to yellowflag a race for track debris!
Another thing on the cardamage are windows... they shoud crack instead of just warping when you roll you car, so, considering race car construction generally has shatterproff glass on a rae machine, it doesn't have to break.. all we need is texture based shattered (but holding) windshields!
Also... broken headlights/taillights would add to the effects, along with literal brokenness in functionality (so you can't flash another car if you already smacked the light into a barrier at 100mph, non-functional broken tailights etc...)