I purchased my car last fall and am getting around to sorting out some issues from the previous owner. One of them is the rear window windlace where it goes down the sides of the rear window is sagging. One of the problems was the small piece of plastic at the bottom corner was cracked and I replaced that. I was wondering if using some sort of adhesive would keep this from sagging . I thought of some sort of contact cement or armaflex 520 might work.

Any ideas? There really isnt much on the internet about how this is supposed to go on.