Not sure about what the silver box is, but the tank for hydraulic oil is for the self-leveling rear suspension. Brake fluid goes in the reservoir on top of the master cylinder. I don't know about the "flagship" sticker, but I know that Mercedes (for a very long time at least) had a sticker at the bottom left hand corner of the windshield reading "A Daimler Benz Product" and below it was a reproduction of Gottleib Daimler's signature. The newer version of the sticker reads "A Mercedes Benz Product". I wonder if the latest version says "A DaimlerChrysler Product"