For most of these promotions, the university/auto dealership doesn't care if they win it or not. They buy insurance on it, so it really makes no difference one way or the other. It's the prize insurance company that pays up.
The more I think about this, the more hypocritical I realize the NCAA is. Think about it.
All these players work their asses off in practice, in the weight room, training in the offseason, going to study hall, classes, etc. and they get nothing out of it besides a scholarship (some don't even get that) while the NCAA makes bank off them.
Then some random kid comes in and makes a few shots and wins a free truck? What about his ammeter status?