Why so much research and development when the best aerodynamic shape is well known by car manufacturers. OK, seen the pictures on this thread it is understandable because they have gone very far with the XL1, it is perfectly crafted. It could perhaps serve to develop new cars.
A simpler aerodynamic shape with a small engine (hybrid or not) and no other fuss around it. Make it affordable. An example is that Honda Insight. That would show real courage.
But then again the question arises: would such a concept appeal to a large enough audience
in these times of cross-overs 