How are these things held on?

My right rear door panel is loose at the top left. (Like above the speaker)

I was comparing it to the left rear door panel and I can't seem to find anything that's missing from the right side. Is it simply that horizontal metal bar around the window?



...And I can't unlock the door from the inside--I have to do it with a key or with the drivers-side latch. Anyone know what's goin on there?

 

The Rear door panel should just latch on top.

The front one you will have to remove and inspect the door lock setup.

 

But by "latch on" I mean where? I'm not sure if a clip is bent or broken or whatever but the thing is lose and I can't figure out *how* it latches on.

 

The top of the door panel should wrap around and slide into the top of the Door.

 

I circled the part I assume you're talking about in red:


(Not my interior--just a pic I found)

The metal bar under that rubber seperator is loose and I haven't figured out why or how to tighten it back up.

 

Remove the Other side rear one to look at it and see what is missing compaired to the other one.