I hate to be a wet rag on your fire here, but keep in mind that these winglets you are discussing are all fine tuning enhancements on vehicles which are very aerodynamic to begin with. They effect only a small amount of airflow around the vehicles. Putting these things on a pick-up truck which has the aerodynamics of a shaped brick is IMHO a waste of time and energy. You need to do things that affect mass amounts of air in order to see anything that is going to make an appreciable difference. Building a 2 ft kamm sorta thing on the front of your cargo box would probably net you the biggest easiest gain, a full on aerocap, would be better yet. Anything you do will be optimized by following the template.
Just sayin.
