I ran into an interesting (to me anyway) article about a fellow who added solar panels and other related equipment to his Prius. Looks like a viable method to add MPG if the funding occurs. He predicts a market cost of $1000 (Canadian) for a production model if it gets to market. Take a look.
http://www.evworld.com/view.cfm?section ... toryid=898
http://www.evworld.com/view.cfm?section ... toryid=898