You mentioned Thule, which might be the answer to your wind noise problem. One of their fairings in the small version would fit between the factory rails, and is compatible with square bars. Something like this...
@WoodyCreature , where did you get the brackets you used to attach the 80/20 to your factory side rails. I can think of a few ways to utilize those on my Prinsu rack.....thinking maybe awning mounts, etc.