When you are buying a car (new or used) you are really involved in three negotiations. First is the price of the car. Who will give you the best deal. Second is the price they will pay for your trade in. Can you do better selling it privately and is it worth your trouble. Third is the price of the financing. Interest rate, down payment and length of financing. Finally, if you have the ability to pay cash for the car, what interest are you foregoing to pay cash. Get all the figures and find what works best for you. I've been a USAA member since 1963 and have used them for financing multiple times, but for the car I just bought, they couldn't come close. Dealer financing was the way I went this time, but next time I'll let USAA try again. You never know until the numbers are on the paper.