[critical_level2]

I will agree with the others.

Another trick I use:
Bring a friend, wife, husband, etc. If you have a friend who is a mechanic, even better. Have them play Devil's advocate. So some interest, but at the same time have them bring up all sorts of reasons why you shouldn't buy it or go somewhere else. Don't let them get to over the top though. This has helped me and my friends get the price we were looking for or sometimes even lower.

Most importantly, always be ready to walk away. There are millions of cars out there for the picking.