Left over part from removing window trim on W205 Estate?

[joq3]

I just tried wrapping my window trim and when I went to put it back I got one part left over which I cannot figure out where it goes. Please help.
I am thinking it might be from either the front or rear door window trim, as I separated the rubber from the metal trim. But I could not fit this part anywhere?

Any ideas?

The spare parts list does not show the window trims in an exploded view.

Any idea where to purchase new clips for the trim at the far back of the car?

 

[Scooby_Doo]

I thought MFI had closed years ago.