Car sales prospecting ideas?

I sell cars at a pretty good sized dealership in a city of about 100,000+ people. I do pretty good with it, but I still would like a little more. That's were prospecting is coming in. Usually myself and another salesman will go to the local mall and hand out cards and talk to anyone who will listen. It's starting to get a little old and I am not really getting any good solid leads out of it. I would like some ideas on how else I could prospect around town. I already have a myspace page set up all for my business and that has helped me a lot. Also I am sending out letters constantly. Any ideas would really help

Use Craiglist.org. It's free and a great way to get your name out to people looking for vehicles. Just takes a little time to post and you cannot have too many duplicate postings within the same day. Costs you nothing!