[kach22i]

You could go a little crazy and build your own (gas saving form).

Commercially produced aerodynamic pickup bed cap - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com






Similar to above: A new record MPG for Ford F150 with aerodynamic cap!
http://ecomodder.com/forum/showthread.php/new-record-mpg-ford-f150-aerodynamic-cap-3539-4.html

Driving home from Denton, Texas to Little Rock last night, I set a new record for the aero cap, 25 mpg!.....................2006 F150 with the 4.6 liter v8 and automatic transmission.