for anyone interested. These are interesting as well.
http://www.youtube.com/watch?v=o3wcJweOd-8
I have been watching the development of these for over a decade myself.  I have interest in them and want to see where progress takes them... 
Short city drives would be alright but what about longer drives on a trip for example?  Somehow we got to get that air compressor inside the car to provide FUEL supply.