Motor Vehicle, Mobile Home, Off- Highway or Vessel Description. Year. 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.Once you've both filled out a Florida Bill of Sale, follow these next steps for registration of the vehicle: Write out the title with the previous owner. The bill of sale or receipt for any engine must also include the year of the engine. Write 'Gift' on the selling price line, as this vehicle was a gift and FL doesn't collect tax on gifts. A bill of sale, proof of purchase, proof of payment, or proof of sale, is a legal document that is used to transfer ownership and verify a sale. I purchased a vehicle from a private seller in Illinois, but the seller could not find the title. We signed a bill of sale and had it notarized. Motor vehicles, vessels, mobile homes and trailers must be registered at the point of purchase and a certificate of title issued as proof of ownership.