year and model???
i'll speak from my view on my 87 420sel .that clip the clip holds the window wiper to the chrome strip on the door.
take that clip to your dealer and buy 2 pcs. then look at the chrome strip and either tighten the clip up on the side of the clip that snaps over the door edge. you may need to buy all the chrome clips.
once you have the clips firmly held to the chrome strip lay it on the outer door lip. be sure that all the clips line up where they are to go as well as being over the lip of the door. you will need a rubber mallet. the palm of your hand won't work. now strike it firmly straight down (you'll need the window open). smack it good and get all the clips all the way down.
now the chrome piece will stay down and the rubber window wiper will hold the glass from rattling.
1972 350sl Red/Blk 117k
1988 420sel charcoal/Blk 140k
1987 420sel gold/tan 128k
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Pound it to fit then Paint it to match!
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