My parents waited until i was 17 and had already had a year of driving under my belt before they let me buy my car. I drove an 86 olds cutlass all through my junior year of high school. I bought my stang in september of this year and i am graduating this year
. At the time of driving the olds i wasnt liking my parents decision but in turn i think it was a good one. After hearing so many tales of 16 y/o's who just got thier license and have a fast car wrecking it, i can see that it probably could have been me.
So i think you should keep it as a weekend toy and get him something slower to drive until you know that he has more experience behind the wheel.
Later,
Nick