Leasing a 2011 Lincoln MKX, and saving $10000 off of MSRP.
The sales person made the difference I think. He knew the vehicle and responded well to my questions and requests. Even as far as pulling vehicles into the service bay at night on short notice so that my wife and I could look them over.
Buying a 2011 Ford Fusion, and saving $1500 off of MSRP.
I negotiated by email. There were only 2 of the type I waned left in Ontario, so he gave me a list of the vehicles and options. I used the report to put an offer one one at what I thought was 3% (bottom line price) and they came back with $300 more (it turned out to include etching, which they charge $400 for, but must have a very high mark up) but was negotiated on bottom line price, so any extras like that did not change the purchase price. (Savings were much, much better with the factory incentives, but these were published and available for anyone to use)