Google "Corvette Birdcage Rust".
Where fiberglass meets metal is often a problem, in our rust belt area "project" Corvettes with strange body swelling/lines breaking out in odd-looking spots come up from time to time. You don't want to buy that one.
Until the Vette moved to KY most had body defects and paint issues.
Materials and production improved there to where it is not an issue anymore.
As for Corvette rust there is still more metal in a Corvette C3 vs a Chevette. Metal just rust no matter what body covers it. Same on the Fiero as under it is all steel and the body is mounted in epoxy mounts.
The hood on my GT-faux (actually a cloned LeMans) is fiberglass (long ago forgot the manufacturer). Now, hardly any of the sheet metal on the car is really all that straight, but the hood was extremely "wavy". And, as the first or second most visible area of the car (especially to the driver), it was just too much to bear. So we sanded. And we primed, and we filled. And we sanded again. And primed again. And we repeated numerous times. And still, just when we thought we had it and applied the base color, the storm would come again and the "waves" would appear. I can't remember for sure, but I think we painted that hood maybe 6 or 8 times. Possibly more - I think I may have blocked out the memory of it all.
Metal working on body panels is hard enough. Doing the same on fiberglass is a WHOLE different animal, and VERY much harder. It looks okay (well, the whole car barely looks "okay"), so I guess we won the war. But I'd think twice or thrice before I undertook that again. 🙄
Yes, I was kind of schooled by the local wrap guy who told me that the prep for a good wrap job was almost identical to prep for paint. On the upper surfaces of my pick-up, where the clear coat has flaked off, I'm considering wrapping, but I told him I'd do it in "camo" so as to not have to worry too much about surface imperfections, they'd just disappear into the pattern. He frowned at me, and said, "good luck with that". 😋
This was my experience with the Europa. I was in a JPL Champion edition and found the body panels worse than many kit cars over the years. But it was molded for light weigh and most panels are thin and lack much support. It may not be a quality issue but more a weight issue know Chapman.
The Corvettes that are restored correctly from the past often will reproduce fiberglass issues where they are know for them. Back in the day they were glued together in St Louis and often seams would be still seen in some areas. Victim of mass production.
The greatest challenge of composite panels like this is door gaps. Even the Saturn with the molded panels had issues with wide gaps as the bodies would move with sun and heat.
The C8 gaps are a testament to the level of panel quality today on these new SMC panels. Same on cars using Carbon fiber.
I'm sorry, did I miss something? I was reading this comment and then I got to the words, "1963 Corvette Slit Window Coupe..." and I must have sorta drifted off. My body was still sitting here at the computer, I guess, but my mind and spirit were out on Route 66 in a red Split Window, rowing through the gears, tooling along with Linda Ronstadt crooning out of the stereo, and an ice cold Coke waiting for me at the next drive-in. I seem to have been out there for quite some time, 'cause when I came to, it was no longer 1966, and I was sitting in a leather recliner instead of a bucket seat. Fill me in on what happened while I was gone, willya? 😋
The key to covers is to have the right one for your needs and use. Not all covers are equal.
Also a Cover is not a replacement for a garage either as some like to try to make them.
I cover my car inside but I use a high quality light cover as it is so easy to put on and off and easier to store. Also I have one cut for my car.
Universal covers are a pain and fit poorly. Also if you use a heavy outdoor cover inside it can be a pain as they are bulky.
Dirt should not be under the cover. If it is you covered a dirty car and that is a major no no.
Look it comes down to knowledge of the person doing the repair and the quality of the panel.
SMC panel like on the new Vettes are near perfect out of the mold.
Hand laid glass it depends on the person doing the work.
My body is SMC with no issues. The hood and rear scoop for my car are hand laid and they needed work. The hood was horrible. Air pocket issues etc.