Very nice abslayer, this is closer to the form and location I had wanted to take, looks like it will split the high pressure area created by the windshield and camper very well. I couldn't achieve your contour as I wanted the cabover deflector to be at 45 degrees so I could mount a separate deflector in the area where the front jack are located. The dually extensions made a natural 45 degrees for me to mount a deflector to. This also then allowed the front lift legs to be at a 45 degree angle further reducing the drag.
I have not experienced the vacuum (low pressure area) effect described by sleepy. I can see how this could occur but have not had any water, snow or dust come up between the truck and camper window. Also I have never seen a dirt line vertically back on the sidewall of the camper that is also described by sleepy. I have only drove truck/camper combination for short distances without deflectors (a few 100 miles) so can't say about vertical dirt line.
Wind noise was main reason for my deflector as it was terrible, now the wind noise is same with or without camper.
On 3 different 10000 mile plus trips, fuel mileage has been 14.9/15/15.1 mpg hand calculated, total miles divided by total gallons used for trip, this is at average of 58 to 60 mph speeds. I have no non deflector mpg figures however I may remove deflector for a shorter trip this summer.
In edit I should also mention that Myth Busters have had a recent episode that directly related to birds flying in V formation, they used a number of airplanes simulated the V formation and monitored fuel usage. It does indeed reduce fuel consumption and it does increase turbulence for the following aircraft similar to the Air Tabs venture effect, if I recall correctly, I only was able to watch part of the show.
Found the episode here, I hope I have figured out how to make a clickable link.
http://www.tvids.net/watch163/MythBusters/season-09-episode-22-Toilet-Bomb
