Your trivia for the day: The official dealer-technician term is "FPP", for *ahem* "Flimsy Plastic Part". Apparently the usage became so common that MBUSA had to ask techs to stop using the acronym in their warranty reports. The BFS is a type of FPP... the FPP term applies to most any oddball plastic widget. I believe the term "BFS" was coined on an old MB diesel email list back in the dark ages of the interwebs, before forums crawled out of the primordial ooze...