My 17 year old son has morphed into an @$$, HELP!?

He's always been an easy going, quiet, artistic type. He is popular, keeps good grades and is responsible at his p/t job. Since he bought his own car he has turned into a real jerk. He thinks he can keep his own hours, have no household responsibilites, ignore curfew and now he's been caught by the police, drinking. He says he doesn't drink often and isn't using drugs but his personality has changed so much since he entered the 12th grade. We used to be very close; we talked about everything, laughed and enjoyed each other. He now doesn't even look at me, won't talk to me but writes in a note to me that he is hurt.Unfortunately, I have no idea what he is talking about. He is angry all the time or completely withdrawn. He avoids being home.He is hyper sensitive about everything I say and do to him or around him. I feel like he is embred of me, but I really give him (maybe too much) space. My friends & the teen court officer says it's a normal phase and he'll out grow it, REALLY?