[disneysteve]

What I've done in the past is to find the best rate, as pearlieq suggested, then go into the dealer with that info in hand. Each time, their finance person matched the offer. It was just simpler that way to handle everything in one place.

Remember, however, that you should first negotiate the price of the car. Don't tell them about your downpayment. Don't tell them about a trade-in. Don't tell them how you plan to pay for the car. Don't tell them where you will be getting your financing. Until you have agreed on the price for the vehicle in writing, you should not discuss the financing at all.