92 300CE 124V Sportline, the boot bumpers for some reason started oxidising under their plastic cap/covers. decided to replace and the replacements are solid rubber blocks (obviously an update/upgrade). while doing this i noticed the plastic guards that they screw onto/against needed a clean. BIG surprise i pushed the plastic pins out that hold these on major amount of dirt/mud underneath these. caused by runoff when washing car i guess over the years. so im thinking im not alone on this so my advice to all owners of mercs of this vintage should check as well as its seems to hold a lot of dirt and could be a rust hot spot IMHO