A Pennsylvania vehicle bill of sale is a legal document formalizing the sale and purchase of a motor vehicle between a buyer and seller. The buyer and seller should meet at a notary, tag service, or motor vehicle dealer to ensure the title application is completed correctly.Learn about bills of sale in Pennsylvania for vehicles, firearms, animals, etc. Bill of Sale: This document outlines the transaction details, including sale price and date. This form below is designed for use on upon the sale of a motor vehicle or automobile. If there are any deposits or down payments, specify those amounts as well. We've outlined the five steps and forms required for how to sell a car in the state of Pennsylvania so you can sell your car quickly for the most cash. Residents of Allegheny County must pay an additional.