By signing this contract, I choose to purchase the motor vehicle on credit according to the terms of this contract. 2. Odometer Declaration.A vehicle purchase agreement or vehicle contract is very important. Here are the templates that you can download and print. Information you can expect to fill out includes the car's VIN, make, and model, the name and permanent address of each party involved, and the sales amount. A Texas Bill of Sale Vehicle Form is a formal document used to record the sale and transfer of ownership of a vehicle from one party to another.