You do not need a bill of sale and you do not need a notary. I recently bought a car.We provide mobile notary services in most parts of Maricopa County and some of the outlying surrounding areas. For example, notarization is required for a motor vehicle but not for a boat or gun bill of sale. AZ Docs provide mobile notary services in Phoenix, Arizona. Our traveling notary services are flexible and convenient to schedule. Seller Name (first, middle, last, suffix). It's also a great idea for the seller to prepare and sign a Bill of Sale, and have it notarized. To have a car bill of sale notarized in Arizona, both the seller and buyer need to be physically present in the notary office.