You do need bill of sale. You may want to write up an extra thing that both of you sign to CYA but that's not for the DMV.You, the Buyer (and Co-Buyer, if any), may buy the vehicle below for cash or on credit. The two documents used most frequently for purchasing and selling real estate in the Bay Area are the PRDS and the CAR purchase agreements. When buying a vehicle or equipment for your business, use this Vehicle and Equipment Purchase Agreement to protect yourself from unwarranted liabilities. Below, we've outlined the steps and forms required for how to sell a car in the state of California so you can sell your car quickly for the most cash. The entire terms, conditions and exclusions, including but not limited to, your duties, are included in the written Service Agreement. This article highlights recent changes that CAR has made to its purchase agreement.