I had some PDR work done on my passenger door this weekend and the technician claimed he found this piece laying in the bottom of the door. Whether or not I believe his story, I would like to find out where it goes. I took my driver's door panel off hoping to find the same piece on that side but I couldn't see it. Can anyone who has had their window out help me out? I'm pretty positive it's supposed to guide the window, the question is where does it go? Thanks!

This side points towards interior:


This side points toward exterior:

 

It clips into the upper door moulding, towards the rear (the long black trim piece on the outside of the car that runs the entire length of the door)

Very common for it to be found in the door bottom.

 

I had to reattach both of mine, when I put them back onto the mounting spot I used some black gasket sealer so they don't fall off again, they are only held in place with those two small clips on the sides, friction fit.

 

That makes sense, thanks for the replies! Do I need to take the moulding off to reattach it? If so I'm guessing I should buy new clips so I have replacements handy if/when they break?

 

Only thing you need to remove is the door panel, moulding does not need to be removed. With window slightly open, you can clip it right in place from underneath.

In all 3 of your pics, the part is show right side up (correct)

Top pic shows the side that faces the interior.

Second pic shows the side that faces towards the outside of the car.

You will find about a 2" section of the moulding notched out, about 8" away from the rear of the moulding. This is where it goes.

Have added notes to your pics.