This form certifies the purchase price and determines the sales tax you must pay when registering the vehicle. Watch this before you finance your next car (former dealer explains how to read a purchase contract)A vehicle sales agreement is a lawful arrangement summarizing the terms and conditions of a vehicle sale between a customer and a seller. 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. Note: This form must be downloaded to your device in order to be filled out properly. It must be opened in Adobe Acrobat Reader. Make Life Easier with Expert Automotive Financing. 2. In the Preferences dialog box, click Forms from the list at left. 3.