An Illinois motor vehicle bill of sale documents the purchase and sale of a motor vehicle between a private seller and buyer in the State of Illinois. Motor Vehicle (DMV) Bill of Sale Form Affirms the information contained in a transaction of a vehicle for a payment amount.Get Illinois bill of sale forms and learn how to transfer ownership of vehicles, boats, firearms, and other personal property from one party to another. 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. An Illinois bill of sale details the private sale of valuable items between a buyer and a seller. Use our Illinois bill of sale forms to legally buy or sell personal property in the state of Illinois, including a car, firearm, or trailer. The form details the sale date, purchase price, and the names and addresses of the parties involved. Basic bill of sale form in Illinois to be used as general BOS document and customize the sale contract as per your transactions and requirement. You should attach a copy of the bill of sale as proof of the purchase price.