Constitutional Amendment

If I had the opportunity to add and amendment to the Constitution, I would want to change the driving age. Right now the age is 16. I believe the age should be lowered to 15. But the exception, is that you must be in High School, and maintain a  GPA of at least 3.5. This way, people who need to be able to drive, for things like school transportation, sports, etc. would be able to. But it would be justified through having a 3.5 GPA, because then the kids would have a decent common sense, and would give the students something to work towards, and a better reason to work hard and earn that 3.5 GPA. Of Course, they'd still have to pass the regulation driving test, so the driver would still have to be taught and be able to drive properly.