Although I dont have a wind deflector on the top of my truck I do have a cap on it and you can see from the bug splatter where it has forced the wind to when on the highway. In my opinion if you dont have a cap on the truck a wing will be a waste of money as the air will start to drop before it clears the trailer.
2004 Chev Silverado Duramax optioned past the max. 2009 Jayco Eagle 308 RLS 765 watts of solar, 6-6 volt batteries (696 amp hour), 2000 watt (4000 surge) whole house inverter.
140 days boondocking in 2016
211/2015, 196/14, 247/13, 193/12