Paint Stains

So, I washed my car today because it's white, and it's a beautiful day, and my car has all these black marks that look like dirty water dripped down the side of my car. After I spent $8 at the local car wash I come to discover that the black stuff is stained into my paint. I can't get it off. Has anybody had this problem before? Does anyone know any good tips to get rid of these stains? Or am I just stuck with havin to repaint the whole car (which it probably needs anyway, especially since i hate the color). Please help.

Try a cleaner wax. If that doesn't work, try polishing compound. If that doesn't work, try rubbing compound. If that doesn't work, try wet sanding with 2000 grit sand paper.