I live in Colorado, so NOTHING rusts. Every time I get computer parts from swamplands like Florida or Washington it always tends to be rusty. Where do you live?

I live in Portugal, but this is the only card i have showing these symptoms. That's why i find this situation a bit odd, Besides it's not just any video card, it's a freaking voodoo5 5500 that could loose some value if i eventually decide to seel it one day 🙁

I have a V5 5500 AGP that is even more rusty than yours. It has corroded in the same places (rear plate and the bracket at the power connector), so it looks like those parts were made from poor-quality steel. When I bought it a few years ago I assumed it was stored in a damp cellar, and I got it for a low price (~15 €).

Well after a few google images searches i have found one or two more examples or similar cases.
3Dfx really did some dubious choices after voodoo2\banshee but i never thought material choices were one of them.
Curiously (not) some ebay users take the most tactical shots of their voodoo5 cards for sale, i can't notice any rust on those 😀

My two V5 5500 AGPs have rust like shown in both of your screenshot, but both still work fine. Interestingly I have two V4 4500s that show no sign of it.