Skid plate/belly pan

[Billett]

I see an awful lot of posts about improving mpgs in these trucks by doing all kinds of crazy things, but has anyone ever decided to build a skid plate or belly pan for these trucks to try and improve the absolute lack of aerodynamics on these things? I would think there's enough room to build a pan all the way back, not just the front. i know a lot of the eco-modding crowd does this and claims 2-3 mpg increase on cars that are already pretty slippery.