Seriously. This history of Dr. Dre is WONDERFUL.
Lonzo Williams would loan Dr. Dre money, not unlike how Combat Jack would loan a young Damon Dash money to take cabs, in the years pre-Roc-A-Fella Records, so he didn't have to be seen taking the train. Dr. Dre wasn't concerned with his appearance, disco outfit notwithstanding, so much as he was broke. Public transportation isn't as good in LA, and there's even a song about how no one there walks. Lonzo let Dr. Dre drive one of his old cars so he'd have a way to get around.
Dr. Dre would get tickets driving Lonzo's car and wouldn't pay them, either because he figured it wasn't his car, so it doesn't really count (classic hood logic), or because he's just one of those guys. We've all got that one friend who's in and out of jail on the reg for no reason other than owing the city money. Eventually, LA would put a warrant out for Dre's arrest, he'd get pulled over again, and he'd have to go to jail.