Dave, your '76 GRAN Fury was a C Body though. My guess would be someone added the sunroof post-retirement. I didn't think CHP had '76 Gran Furys.
Now lMop ... no negative waves here
Why so ? Alignment issues ? Bad seals ?
Install was done third party and was sloppily done in a lot of instances. As said, there is absolutely no collector value to be had in the car, well optioned or not. If you want one, just find a clean car with color you want. Have a sun/moon roof put in aftermarket.
There are a couple of extremely clean cars for sale on fmjo. Darth Car comes to mind. Black on red.