Yeah, it's true that cf is much more expensive per pound than steel, but the trade-off is that the 1/X uses a lot fewer pounds...
OTOH, concept cars are just that ... concepts to get the creative juices running. It will be interesting to see how much of the 1/X's technology makes it into production hybrids in the coming years.
__________________
Best tank ever: 72.1 mpg in February 2005, Seattle to S.F.
New personnal best 'all-city' tank June '08 ... 61.9 mpg!
Thanks to 'pulse-n-glide' technique.