By signing this contract, I choose to purchase the motor vehicle on credit according to the terms of this contract. The Texas bill of sale form verifies the elemental facts of the sale of personal property in exchange for a predetermined compensatory amount.Odometer Declaration. A vehicle sales agreement is a lawful arrangement summarizing the terms and conditions of a vehicle sale between a customer and a seller. When buying a vehicle or equipment for your business, use this Vehicle and Equipment Purchase Agreement to protect yourself from unwarranted liabilities.