The extension is easy to install and sell themselves. Basically, you have to remove only two caps, insert the Verlängerun and already the whole package can be fixed. Unfortunately, to install two extensions on one side only works with physical pain. Hauck is probably the view that this is not a good idea, and therefore has stuck a cap on the extension. At least they can only be removed with a screwdriver and some Abrutschern and a lot of strength. Why this should not be made, no idea, because this extension also fits perfectly into it. Also a double extension is absolutely stable. As stable as the normal door guard permit,
Basically, there is nothing to complain about. Delivered without instructions, but even a child would understand the ulterior motives. In short a good addition, if one of the grille will not fit on the length.