What is a window sticker addendum?

An addendum is a second sticker some dealers place next to the official window sticker. It lists dealer-added items such as accessories, protection packages, VIN etching or a market adjustment, with their prices. Unlike the manufacturer's Monroney label, the addendum is created by the dealer, and its items are often optional or negotiable. Ask which items are already installed, which can be removed, and get the final out-the-door price in writing.