What do you do when you know a 13 y.o. boy is driving his parents car illegally on the streets?

I am 14 years old and while attending a sports game for disadvantaged people (for community service), my friends and I met a 13 year old boy (who, incidentally, used the f word practically 5 times per sentence) and his friend. He described how just then he had narrowly avoided being caught by the police driving a car. He and his friend each took out a pair of keys. We were rather shocked, but didn't know whether to believe them, so we watched him go out to the car, his parent's car, turn it on, vroom it up, turn on the music, and move it back a metre or two. He said that his parents sometimes let him drive the car. He definitely wasn't bluffing about it, because he described his driving experience so vividly, and he actually had the car keys on him, and he knew how to start and move the car, he didn't seem like a deceptive person, and he couldn't have maintained the bluffing for so long.
My friends and I decided to mention it in passing to a teacher, but the teacher didn't take much notice of it. What is the right thing to do in this situation? Do we have an obligation to do anything if we know a juvenile is likely to be illegally driving a car?
Thanks.

You don't have any obligation, legally, to report him. However, you may file a police report. The police probably won't do much unless they catch this individual in the act of driving. There's no law against him having a set of car keys, but you are correct that he should not be driving.

tell the police..tell your parents? tell someone that can do something about it. it's not safe at all for the kid driving the car or the innocent people that he can crah into!
:[

Ready! Aim! Fire!

Tell his parents.

Had this been my child, he'd have gotten the whooping of his life.

?

Get him a NASCAR permit!

i think that you should report them before they get into an accident and hurts someone

Just because he had the keys doesn't mean he actually drove the car there. It sounds like he was trying to show off and impress you. When my son was young I would give him my keys in case he wanted to sit in the car and listen to music. He put the car in gear to impress you. At the end of the game did you actually see him Drive off in the car? If so then I think you should have gotten his license plate number and notified the police.

Please, since the teacher didn't care enough, please go to your school counselor. It's not so much getting the kid in trouble as it is a safety issue for everyone else. At 13 or 14, he obviously hasn't had driver's ed. He may very well know how to drive, but does he know how to handle the vehicle in serious conditions?
Yes, his parents are still responsible for his actions (he is a minor in the eyes of the law), and may be in more trouble than he will be. I'm sorry, but I'd much rather see the parents fined for the child's actions than run the risk of the kid killing someone (or himself) because he doesn't really know how to drive.