If there were a such thing as "flat chrome" then I would actually think this process makes sense. Actually maybe there is? You couldn't just polish the bare metal to achieve such an effect though because, as swamp mentioned, there are three different materials used for the body panels, and plus you can't polish plastic anyway.
Maybe nickel plating? Hey as metal plated processes go, anything would be better than shiny chrome (or gold)? Brushed aluminum would probably be cool too, but again, you can't plate something in aluminum (or at least I don't think you can).