The truth is, street racing is part of the hot rodding culture. And if that's how he was raised for the last 16 years, that's just who he is. A few lectures aren't going to change anything. My dad tried the same shit, and it didnt work. If you're not comfortable with it, just tell him straight that until he's 18 and is responsible for his own actions, the car only runs at the track. Let's be real here, in a 16 year old guy's world, Mom & Dad's words don't mean shit on Friday night when he's had a couple of beers and wants to impress his boys (or better yet some chick he's trying to bang). Bottom line: don't sell his car, just put him in something slow until you're no longer responsible for his fuckups. Tell him you love him, but you're not willing to lose all of your shit so that he can go racing.