I hear a lot of people asking about pricing, so I just wanted to share my experience with carbargains.com
My girlfriend (she bought a Jetta) and I both went through this service, after we heard on 60 minutes or 20/20 or one of those shows that they're the best at getting cheap deals.
You pay $165 and in about 1 or 2 days, they fax you back a dealer invoice pricing sheet, and a list of dealers in your area and a price they will commit to. For a 323ci, I got a couple of dealers commit to $1000 under MSRP and a couple at $2500 over invoice, regardless of equipment. This was in the SF Bay Area, so I'm pretty sure it was a good deal. If anything, it gives you a bargaining point, a price to work from when you negotiate for your car.
The service is great. I hope this helps all those still in the negotiation process.