My Dad used to own a car yard and I sold new and used cars for major dealerships for a couple of years. I also still wholesale cars and I have learned from this experience that the customer will pay more if they really want the car.
If you are prepared to walk he will be more negotiable. Also have you shopped around other dealerships for the same car? If he knows that you can get a better deal elsewhere he will aslo be more flexible. It's all about his bottom line.
Good luck and I hope you get a really good deal!
