1 If you're financing your purchase ; 3 The actual vehicle purchase agreement ; 4 Buyer's trade in certification ; 5 Warranty disclaimer and documentary fee notice. I left with a signed purchase agreement from the dealership.You'll need to sign the car purchase agreement (or dealer bill of sale), the title, an odometer statement, and sometimes a damage disclosure statement. 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 certifies the purchase price and determines the sales tax you must pay when registering the vehicle. At PandaDoc, you can access a free car purchase agreement form template to prove your ownership of the vehicle. Sufficient income, credit and a history of paying debts on time are among the top criteria lenders seek in an applicant.