Kevin D. alearted me to this thread. I liked Sherman's photoshop idea of the fuel cell. With a little work on proportions, ie. lowering the top a little, the unit would be great.
As to my avatar, with the trunk, I did the above photo shop work to show other owners an idea for a utility trunk rather than a fuel cell. Could work either way or both as noted by No One. Here is another photo shop picture I did at the time (4 years ago) :
The original concept was to replace the rear seat and tail rack. To afix the trunk by using the tail rack mounting points. I dropped the idea and bought a Corbin Smuggler at about $700. I wanted a trunk now and then dropped the idea of making a fiberglass unit.