I thinks this topic has allot of room for exploration. Thanks to all of the members that have stepped up, and said what if we did this.... And were willing to open their wallets and try something different. Take a product that was designed for one thing and test it for something else.
I looked at the air foil design and thought that was really a good design. I am in the same position as Art with a small clearance area above the cap, less then 2". So perhaps a modified air foil, tabs would do the trick.
The other areas for drag reduction could be the front jack area and the flat area behind the truck tail lights. Thanks to all of those that posted with their ideas.