You buy a used car for $20,000, using a car loan. The loan is to be paid in 13 monthly payments, beginning with the first payment immediately (the first payment is the down payment). Nominal interest is 12%, compounded monthly. The day you make the sixth payment, you sell the car to a friend. Your friend pays off the rest of the loan immediately and, in addition, pays you $3,000. If there are no penalty charges for this early payment of the loan, how much will the car cost your friend?