You'll need to sign the car purchase agreement (or dealer bill of sale), the title, an odometer statement, and sometimes a damage disclosure statement. 2. Odometer Declaration.This Motor Vehicle Purchase Agreement outlines the details required for buying a vehicle. I'm gonna break down all the terms and conditions so you can understand what it means and we're gonna fill that out so you can have a real-life example of it. A confusing and convoluted document that outlines the selling price, fees, taxes, your trade in, and more. Write out your own full name, and that of the buyer. A motor vehicle bill of sale is between a buyer and a seller of a car, truck, or motorcycle. It is signed as the last step in the sales process.