Some years ago I remember reading of a proposed hybrid van or light truck that was to be marketed to builders and other contractors.
You may be thinking of the circa 2003 "Dodge Ram Contractor's Hybrid." Appparently, it never went into production. I thought it was a great idea, and might have bought one...
Wikipedia:
http://en.wikipedia.org/wiki/Dodge_RamDiscription:
http://www.pickuptrucks.com/html/news/ram_contractor.html