The final hurdle you face is signing the vehicle purchase agreement; a confusing and convoluted document that we explain in detail here. Use this car purchase agreement template to customize the financing information for your car along with other required details.Watch this before you finance your next car (former dealer explains how to read a purchase contract) How to fill out the Installment Sale Contract for Vehicle and Equipment? We've put together this guide to simplify car purchase agreements and help you stay protected when purchasing vehicles or selling them. Complete Private Car Sale Installment Agreement PDF in Seconds with PDFSimpli. Fill out the Private Car Sale Installment Agreement PDF form for FREE!