Car dealers make money on the sale of used cars by purchasing them from individuals at a low price, then reselling them to customers at a higher price. They also make money from additional services, such as financing, warranties, and aftermarket products. A car dealer can make up to $6000 on the sale of a used car, depending on a variety of factors, including the condition of the car, the demand for the car, and the amount of money being paid by the customer. The dealer can also make money from additional services associated with the sale, such as warranties and financing.