I found these plastic pieces where the speakers are located in the door panel.

Any idea where are they placed?

 

I'm pretty sure they clip into the bottom of the window somewhere. Bump for the exposure!

 

Those might be broken clips/tabs from the door weatherstrip. Those plastic pieces can break if the weatherstripping is removed/replaced incorrectly. Here is picture of the clips.

 

Thanks man, for sharing those photos and yeah I left them out, I couldnt find where they fell off from.

I am sure they are necessary, but do you guys think they need to be put back on? Don't really know what purpose they serve probably holding down the weatherstripes?

 

Now that I look at your picture again, I am thinking that they are not the weatherstrip clips. I am not sure what those plastic pieces are. Sorry.

 

There is a little slit in the weather stripping on the outer part of the door towards the back of the door. Directly adjacent, on the inner part there is a tab with a felt strip. The two sandwich the window.