well that may be a good thing
I am on version two and I have lost at least 2 mpg @ 65mph on both
I finally adjusted the second to get to a point where I don't loose any @65
at 40 it may be an advantage, hard to tell
so I have entered the realm of flow separation at about 55?!?
I've tuffed and video-ed and am still unclear as to the issue (poor video)
at this point I would settle for looking cool
because driving in traffic with blue foam on the truck & tuffs & a camera taped on the back
...well it ain't exactly pretty