A lot of good points/predictions in this thread.
I think the Xfire will definitely be a 'cult car.'
Out of most newer cars, the SRT6 has what I think is a very high 'collectibility potential.' Low production #'s, style, performance, etc.

If I recall, the Superbirds had a similar fate.
Dealers couldn't get rid of them - and look at them today.
Only time will tell though.