A vehicle payment plan agreement is a contract between a buyer and seller of a vehicle that agrees to installment payments. Middlesex Savings Bank in MA offers auto loans that have low rates and are hassle free.View our rates and let us help you get your new or used car today. I left with a signed purchase agreement from the dealership. Watch this before you finance your next car (former dealer explains how to read a purchase contract) • If you will borrow, what is the highest monthly payment you can afford? A confusing and convoluted document that outlines the selling price, fees, taxes, your trade in, and more. The ownership costs, shown in the table below, provide the monthly allowances for the lease or purchase of up to two automobiles.