I see no reason to pay interest for 2 auto loans when you can pay one off. I also see no reason to buy 2 (assuming) new cars so close to eachother. Since it seems you have already made the decision to buy the car I advice: pay off the first loan (a satisfactory auto loan might make you more attractive on next purchase) and wait until you have $10K (or more) down for the next car (you can also save more for down payment and wait for a good offer such as 0% financing or 1-2%