If you want to make derbies in Derby Arenas (freeroam), you would have to make all the cars chase eachother. This would be absurd. I think there should be a Derby mode to the AI App.
I suppose someone could define an option that makes cars go after the closest vehicle that isn't within a set "too close" distance to make them chase random targets of eachother at once without becoming an instant graveyard.. possibly. Obviously with a few added brains beyond that basic idea.
I've also got a Race mode idea for the AI app. You use random, but the cars are quite slow and they sure like crashing.