Well with my truck there was no rear quarter panels, just like another cab chassis/ flatbed out there. So I was thinking that if i was getting 17 mpg (20 on highway) without any panels, i could hop it up with some fabbed panels.
all this was exposed along with diesel tank
http://s274.photobucket.com/albums/j...t=P1100032.jpg
first off a little prototyping in foam
http://s274.photobucket.com/albums/j...t=P1100042.jpg
then some 1/4 luan just have to blend it to the body tomorrow and paint
http://s274.photobucket.com/albums/j...t=P1100047.jpg
and here is the full view

* oh I also popped off the headache rack, must have removed at least 3 sq ft of frontal area