A thought just crossed my mine with damage now in play. I remember in GTA IV, a group of people held a Demolition Derby which turned out rather well. I'm wondering if some people here have even thought about it or already plan on doing it. I can see it now in the grass of the tri-oval of Daytona.. I don't see myself doing it often but the thought of it sounds fun.
One of the other online races released, ToCA 3, had a very good damage system and people had demolition derbies, cops and robbers, and my favorite, team no-rules races.
Demo derbies are easy enough to figure out, just hit anyone and everyone.
Cops and robbers is about someone being in a slightly faster and lighter car, running away from the rest of the room trying to destroy your car. (Not easy when they can turn around and go backwards, or simply form a roadblock.)
Team no-rules racing usually ends up with 1 person per team running laps, and everyone else trying to protect that person, or bash the other team. That was insane fun and I might try to do it again in GT.