Find out what documents you will need to provide proof of sale and ownership if you are buying, selling, or gifting a vehicle. Clearly print or type all information, except signatures.Below, we've outlined the six steps and forms required for how to sell a car in the state of New York so you can sell your car quickly for the most cash. New York requires that you complete a bill of sale whenever you buy or sell a car privately. A New York motor vehicle bill of sale provides proof that a motor vehicle has been legally sold and acquired in the State of New York. Yes, a purchase agreement is a valid and binding contract in NY IF the dodge dealership signed it. If they signed it, then they are held to its terms. This form below is designed for use on upon the sale of a motor vehicle or automobile. Such a bill of sale is needed to confirm a party's ownership in the car. A New York motor vehicle bill of sale form (Form MV-912) is a legal document between the seller and the buyer used to transfer legal ownership of your car.