Find out the value of your car before you go to the dealer. Compare used car values in the newspaper to get a good idea of value. You will most likely get more for your trade-in through a private sale. Dealers will offer you less than market so they can make more profit at resale (especially if the dealer offers any warranty on used cars to their buyers). If you do decide to trade in your car at the dealership, discuss its value only after you have negotiated the best price for your new car.