Complete and mail the Notice of Sale form. (attached to the bottom of the title) to the.An Illinois motor vehicle bill of sale documents the purchase and sale of a motor vehicle between a private seller and buyer in the State of Illinois. You should attach a copy of the bill of sale or other proof of the purchase price. The Electronic Registration and Title (ERT) System allows you to complete and print an Application for Vehicle Transaction(s) (VSD 190). 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. A vehicle bill of sale in Illinois is used to document the purchase and sale of a car between a private seller and a buyer. An Illinois motor vehicle bill of sale legally transfers ownership of a car or other motor vehicle in the state of Illinois. 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. Transferring Vehicle Ownership.