Documents Needed: Title or MCO: Original signatures required. Acceptable ID is required at the time of title transfer.The proof of sale for a vehicle from a dealer is the Retail Certificate of Sale (MV-50) ("Dealer's Bill of Sale"). What should you include in your vehicle bill of sale? Keep a written record that includes the name and address of the seller, date of sale and vehicle information, including the VIN. Clearly print or type all information, except signatures. Though standard form bill of sales are available online and from your local county tax collector's office, it's also perfectly acceptable to write your own. A detailed description of the process of writing a bill of sale when transferring ownership of a car to a buyer.