W124 - what is this part and how do I fix it?
 

I noticed they are loose and falling off.
Here some reference.
http://i.imgur.com/qteZEcN.jpg
http://i.imgur.com/nWA8O3g.jpg

Thanks

Its plastic trim and the clips may have broken. Is it falling off on both sides?

Actually, I believe it's a metal trim piece that hooks near the rear glass and a screw secures it to the door jamb. As mentioned, under the trim piece there are clips that you can buy at a MB dealer. Remove the screw and inspect the existing clips so you know how many to purchase.

Yea both sides are falling off

You are correct it is metal. I thought it was plastic.

easy fix, get a really strong magnet and put inbetween the exterior "C" pillar trim piece and the chassis, or dump some glue in there. proper fix, locate any broken clips (2 hours if your lucky) wait for them to arrive in mail. (During shich time the piece has fallen off, so now you got to find another trim piece,,,