Custom cars
They think that their pimped up rides are great to look at, but let's face it - these people are a menace to society.
Half the time they'll take a perfectly good car and destroy it by putting a swimming pool in the back or some other "essential" feature. The other half of the time, these children will think that sprucing up a Fiat Panda by adding a spoiler and a loud exhaust will gain them instant sex appeal. Either way it's a showboating waste of money.