Here's everything you need to know about a car sale contract so you're prepared when it comes time to make a purchase. A master purchase agreement is a legally binding contract between buyer and seller, and typically relates to buying and selling goods rather than services.The final hurdle you face is signing the vehicle purchase agreement; a confusing and convoluted document that we explain in detail here. Section 2.01 Closing Transactions. Discover the foundation for a successful and collaborative business journey, ensuring seamless transactions and mutual growth. Non-Recourse Dealer Retail Agreement.