These cars are soooo beautiful that lots of guys get bound up about just driving them (I might get a scratch, it might rain and get the leather wet, etc.). They keep them looking good, but never use them.
The thing is, they're not valuable like an original. They may cost more than most guys think they should, but they're short money compared to a new GT3 or GT4 (shoot, they're short money compared to an "S"). You aren't going to drop the value putting miles on them.