Just a bit more on fuel cells that I've discovered.

http://science.howstuffworks.com/fuel-cell4.htm

With overall efficiency of 24%-32% using liquid fuels as a hydrogen source, fuel cells are in the same ballpark as the IC engine.

Therefore, the IC engine still has a significant economical advantage since it is relatively inexpensive, and available NOW!

The fuel cell combined with regenerative braking and energy storage could be developed into an interesting 'hybrid' car in the future.

Best Regards,
Jim