Writing an Auto Sale Contract. Write out your own full name, and that of the buyer.A vehicle purchase agreement or vehicle contract is very important. Here are the templates that you can download and print. This template is essential for formalizing your vehicle sale, ensuring all necessary information is provided, and creating a record of the transaction. How to fill out the Texas Vehicle Bill of Sale Form? 1. Enter the seller's name and address. 2. Learn about bill of sale laws and requirements for the state of Texas. Get templates for buying and selling high-value items like cars, boats, and firearms. An advertisement agreement template is a helpful tool that specifies a lawful contract between the advertising agency and the business client.