Used-car dealerships often buy previously owned cars that they can sell at a profit, while new-car dealerships typically take trade-ins and may be willing to purchase recent models outright. Some dealerships specialize in certain types of vehicles.
Car dealerships need to justify how much they spend on cars that they buy, since lot space is expensive, and cars that don't sell at a significant profit in a reasonable time frame represent potential money lost. As a result, car owners typically receive less from cars they sell to dealerships, compared to how much they can make selling the car to an individual. New-car dealerships are often willing to purchase relatively recent cars, but most seek high profit margins on the cars they sell, so they tend to favor more expensive vehicles.
Owners selling an older car should take their vehicles to a number of shops, to find the best value. Some used-car dealers focus on specific niches; some primarily sell European vehicles, while others may focus on trucks. These specialized dealers sometimes offer more money for used cars, since they're often able to sell at a higher value. It's also worth looking up the vehicle's value on websites such as Kelley Blue Book, to get an estimate of the vehicle's value.