I know one spoiled brat who was straight cut off of his daddy's money when he turned 21, because he was being an idiot (I've known him since he was about 5 - I'm friends with his parents). They got him an apartment for a year, got him a new car, and said: GTFO
Best thing that ever happened to him.

His little brother got a 1998 XK8 convertible as his first car at 16 (it was 3 years old).