A vehicle payment plan agreement is a contract between a buyer and seller of a vehicle that agrees to installment payments. We offer competitive rates and flexible terms.A confusing and convoluted document that outlines the selling price, fees, taxes, your trade in, and more. To draft a legal payment agreement for a vehicle sale, it's essential to include specific details and terms to protect both the buyer and the seller. Download this vehicle purchase agreement template with monthly payments. Easily customize and use for your car payment contract.