What the heck is this "hook" under rear window?
 

Yesterday we replaced the trim in the rear window - 89 3.2L coupe.
While the window was out we saw this "hook". It was held so that it slid forward and backward. What is it? Located in the lower corner on the driver side of the rear window.

http://forums.pelicanparts.com/uploa...1635340133.jpg

Pretty sure that's a tension wire for the headliner.

???????????????????

!!!!!!!!!!
When my car was apart for headliner and paint I saw these wires in the back corners of the headliner. I guess it helps the headliner keep its shape.

http://forums.pelicanparts.com/uploa...1635346164.jpg

http://forums.pelicanparts.com/uploa...1635346164.jpg

Yeh I know what tension wires are, this wire is coming out of the parcel shelf nowhere near the tension wires.

Yes, this is under the back corner of the "parcel shelf. On the driver side. Below the matting. Very near the hole where the wires (heating and stop light) go down to the engine bay.

Well that's what it is. It's clear on the PET diagram. Part 4A. The others are 6 and 7 (and 5 if you don't have a sunroof). In the OP's image you can see the headliner. Screw it. I'm home today and am going to go take out the parcel shelf and take some pics.

...

Here you go. Each tension wire Part 4A is located at the bottom of the headliner. They are covered by the sides of the parcel shelf and are held in place by the sharp clamps.

http://forums.pelicanparts.com/uploa...1635348793.jpg

okay, this is making some sense now. The "hook" was not tight - could be moved in and out. Was this just for assembly or is it supposed to be tensioned and then fixed or held in some manner?

The wire slides in the "sleeve" where it goes in the headliner. If your headliner is taut in that area then I wouldn't sweat it or pull out the hooks anymore. The only thing holding the wire down is the sharp clamp things that go through the headliner and over the wire.

Yes, I didn't pull on it very much. The window is back in so I'm not horsing around with it anymore. This definitely is in the category of leave well enough alone.