do all negotiations online with multiple dealerships. Go to Edmunds, Kelly blue book and NADA and get find out what you should pay for the car. The True Market Value for the car for the area. Use that number as a base for what you will accept. Once the number has been met, tell the dealer that you have a 30 min to come in and sign paper work and to have everything set up the way you agreed to. I also have had them email me the docs so I can verify the info. Tell them you do not need any new car orientation or any extra warranty or parts for the car so not to waste your time when you come in to sign.

I've also heard of people that have negotiated for the dealer to have the car driven to their home to sign the paper work.