Just to update, I've had mine installed for over 2 years now.
No problems what so ever to report. No rust. Movement is still super smooth. The finish is still like new.
I have to say though, that my car is garaged. However, it does sit outside at the local park n ride 5 days a week, through some pretty nasty winter weather.
A response to anyone that is questioning using with a fiberglass or carbon hood, I really think it has to do with how the dampers open.
If you're not holding onto the hood while you raise it, it will slam up. I imagine that could damage your expensive carbon/fiberglass hood. That's just my guess on the matter though.
I'm still very happy with my purchase, and still recommend these to anyone looking for affordable hood dampers with a carbon fiber finish.