RE: 08 challenger srt8 or 09 nissan gt-r
I don't think the GT-R is going to lose much value. It's a low production, high end sports car. The only Challengers I see being big collectors items 30 years down the road are these limited production 2008's. When it's a full production vehicle, I would see the SRT's retaining their value much better than any of the other trims, but not as well as the first 2008's.