Complete and mail the Notice of Sale form. (attached to the bottom of the title) to the.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. Attach a copy of the bill of sale or lease contract, as appropriate, as proof of the selling price and of any tax previously paid. An Illinois motor vehicle bill of sale legally transfers ownership of a car or other motor vehicle in the state of Illinois. It should identify the vehicle's make, model, year, body type, color, VIN, purchase price, and date of sale. A Car Purchase Agreement Template is a document used to outline the terms and conditions of the sale of a vehicle between a buyer and a seller.