Is there a way to keep enough of the weather strip mount flange in place (while being flexible enough to adjust as needed) & fab a new tail panel to correct GM's great quality control giving a new slate to work on? It sucks getting into panel fabrication to find the fixed panel is out of wack. With this idea, you could even make a pocket that'll give a inner access to mount/remove the plate light while using that voodoo you do so well to look factory like. Regardless, taking a break & stepping back for a moment or two can be what's needed to give a better view on the fix.