I can only remember small details about this movie. There were about 4 teens riding around in a convertible. One of the girls had long hair & tied it in a knot. Some or all of the kids came from a rough school or neighborhood.

You're going to have to try and remember a little more then that..

This is very little information, but the first thing I thought of was “The Outsiders”, 1983.

See here: The Outsiders (1983) (http://www.imdb.com/title/tt0086066/)

I checked, actress Diane Lane has red hair, so maybe that was the movie.

I could be way off, but I thought I would give it a shot.