D.C. Mun. Regs. tit. 16, § 333
333.1 No dealer shall demand or receive any payment for conditioning, preparation, handling, or delivery charges respecting a used or second-hand motor vehicle sold under a retail installment contract.
333.2 Nothing in this section shall prohibit a dealer from including any charge for conditioning, preparation, handling, or delivery in the "CASH SALE PRICE."