Yep. 1984 Fieros had Glass Sail panels with a PVC outside bracket. The mounting studs located on the Glass panels is actually clipped around t he edge of the glass, and the PVC holds it in place. It is a threaded stud, similar to a bolt, and two metal clips attach to the rear clip. There is also a threaded stud up front at the bottom. This is for a nut located inside the frame behind the B Pillar trim. I believe it is an 11 MM or 12 MM...
The later Notchback sail panels in 85 and on were made entirely of plastic, with a press in piece of clear plastic/lexan/whatever you wanna call it that was painted black on the backside. (Similar to the glass)
The FRONT stud is identical to those on the 84s... The rears on the other hand are a seperate plastic clip which pressed into a few notches on the back of the sail panel. Designed to be replaceable, the two plastic studs actually have a piece that protrudes to one side. The only way to get those off without damage is to pull the internal sail panel trim over the engine grilles, as well as to pull the B-Pillar 4x6 speakers. You will notice the stud pushes through, and when the sail panel is pressed into place a little tab pushes out and locks it into place. Pull the plastic sail panels without trying to save these clips will leave you with no way to reattach the panel (GM does not carry replacement clips)..
If you need any clarification, I happen to have my old plastic panels, and a replacement glass panel. I can take photos of everything for you...
PS, I also need to get my hands on two of those metal clips used for the 84 sail panels... Hell, I might even be able to head to Mora and help ya out with em if you can get me those metal clips and any possible parts. Nothing major....