Vehicle Payment Plan Agreement. A vehicle payment plan agreement is a contract between a buyer and seller of a vehicle that agrees to installment payments.Francisco Car Bill of Sale Payment Plans"). It contains information about the buyer and the seller, a description of the vehicle being sold, and information about the transaction, such as price. A Bill of Sale carries more weight than an ordinary receipt, since it requires signatures from both the buyer and seller. Download our free template. The Texas bill of sale form verifies the elemental facts of the sale of personal property in exchange for a predetermined compensatory amount. A Texas bill of sale acts as a legal record that documents the transfer of ownership from you to another party or vice versa. Customize and Download this "Bill Of Sale With Payment Plan". Payment : The bill of sale document should also state the method of payment used such as installments or in full, cash, check, credit card or bank deposit.