What is this part?

[evert]

While repairing my window mechanism and replacing the 4 inch speaker for 5.25inch ones I found a small plastic part that I cannot identify!

The box with cigarettes matches is just for referencing the size.
Any ideas? It might be fallen out of my door but not shure it belongs to it.

[Doug]

I've recently rebuilt one of my doors and removed ALMOST everything -- that part is not familiar to me at all . . .

[Gary]

There is a clip that goes between some of the door opening bars - it could be that. However I don't think it matters if it is missing (it is on my SE now since I rebuilt the doors)