the car shouldn't go to the best one. then the ones who KNOW they can't catch up to the nerds who volunteer and do other things which add "character" points are not going to even try. Or at least they would if they were smart enough.
The prize should be a lottery between the top 20% of the graduating class or something (based on character points or whatever).
And they did mention scholarships. A lot of scholarships these days are based on marks and extracurrics, no difference between giving a $30k for being good than giving a $30k scholarship.
(except you have to pay for gas/insurance on the car)