A couple months ago the plastic rivets on mine broke and it was dragging on the ground while I was driving. I pulled up to the Costco gas station and the guy in front of me at the pump asked me if I knew that it was dragging, which I didn't. I took it across the street to the guys that change my oil, and they ziptied it back up again.
Now, mine was caused by a very large oil leak that eventually ate away at the plastic rivets, which is probably is not your problem. My thought process is that Mercedes put it there for some reason, so keep it if you can! If you don't want to purchase the plastic rivets that put it back up, which can't cost too much I would think, then at least zip tie the thin back on.
I wish I could tell you the correct name for the piece, but for some reason I am drawing a blank. The guys at the oil change place and dealership told me but I can't remember. However, what "cmitch" stated above is pretty much its correct usage (per the dealership).
That is my thought process.