It is possible, in many cases, to trade in a financed car for a cheaper one, but it really all depends on your situation. Consumers trade in cars all the time on which they still owe money. In fact, very few people actually wait until their vehicles are paid off before purchasing their next one. Trading a leased car is a bit more complicated than trading a purchased car. In most cases, it is not practical to trade a leased car, although dealers can make it seem like a good thing to do. Dealers will work the deal to their advantage, not yours. Yes You Can. In a word: yes. You can trade in your old car even if you're still making payments. In fact, dealerships do this all the time for customers. It's so common that you shouldn't even expect a dealership to bat an eyelash when you announce that you still owe money on your current car.