Your link failed to work for me, but I know what the concept car looked like and yes it was very cool looking. That being said, I would not have bought my 2012 Volt, had it hit dealerships like that.
Several posters have already advised that the drag coefficient is greatly improved in the design that is being sold.
For me, I'd love to have in my garage and/or airplane hanger a 1968 Z-28 Camaro (I had in my youth) and a 1970 Camaro Z-28 I got for graduation from high school. But they would just sit there gathering dust. I wouldn't be able to get into and out of them, as I did decades ago. And had the concept car hit the showrooms instead of the model that we see now, I would not have bought one and I suspect not many Baby-Boomers would have either, because it would be hard to get into and out of and the blind spots for those of us wearing bifocals would have been a problem.
I suspect General Motors realized with their first shot at this electric car business, they would need to market a vehicle that older people would be interested in buying, especially older people with arthritis, bursitis and money in the bank. I'd like to see the demographics of what age groups and income levels, are buying the Volt.
I can easily get into and out of my 2012 Volt but it is getting harder and harder to get into and out of my 2010 Silverado 4x4 2500HD and a major feat getting into my Cessna...
Probably, GM, after they have demonstrated they have this new "science" down pat (and I suspect they do, as I'm NUTS about my Volt and telling the world through Flickr stories) they will design a sleek and low-slung electric car for the younger and more "flexible" market...
But I have to wonder, if they did market an electric car like the one in the shape of the concept car, would it be selling as well to a much younger audience?