Chapter 1: General Registration Information. A motor vehicle bill of sale is between a buyer and a seller of a car, truck, or motorcycle.It is signed as the last step in the sales process. California Bill of Sale Forms (3). A California bill of sale is an official document used to record the sale of personal property between a buyer and seller. Clearly print or type all information, except signatures. To fill out the bill of sale form you'll need the name and contact details of the buyer and seller. A California motor vehicle bill of sale is part of the vehicle registration process. Use a free template to write your own bill of sale. Next, provide the names and addresses of both the seller and buyer.