HelenE350

Arrie

This is the head light washer. You have one on both sides.

washer comes out during light wash to spray water on the light and goes back in when not washing. Light washer works with windshield washer but only every so many washer use. In my car this is every tenth press of the windshield washer button.

DubVBenz

a shame they're periodic on the W212 (and later W211s). My 07 W211 has a dedicated button, as did my W208. Previous W126s with the blades would engage with every wash press if I recall.

cetialpha5

That was in a fit of cost cutting. On the W211, it activated after every 5 uses of the windshield washer fluid in 2008+. Headlights have to be on for them to kick on. On the W212, it was after every 10th press. They went away in 2014 when MB switched to LED headlamps. They were only for the bixenons on the W212 although the W211 had them as an option/no cost addition to some halogen models.

OP can just buy the cover, they're not that much. MB also sells them with the correct paint color. Just need the VIN to determine the right part number or ask the MB dealer directly after giving them the vin. Probably cheaper to pick it up locally from the local MB dealer because any savings would be wiped out by shipping charges if buying it online.

BenzV12

Mercedes-Benz W140s also came with the wipers besides washers . From my experience , I don't miss those but rear cam washer could be more useful though