There's been some pretty good posts and threads about lowers, buffeting, air flow from under, etc. I tinkered with many of the ideas until I got something that works so well that all I get now are nice wispy breaths of air around my face. Turbulence wise, it's quiet behind that screen.
Here's what I did. I first bought the Memphis Shades lowers from Eddy, and mounted them up just beneath the screen. Still had buffeting. So I lowered them by swapping sides and turning them upside down. This make the mount much lower, but left a huge gab between the screen and the lowers. End result? Buffeting. So I went out and got some plexi and make up longer lowers using the same MS hardware. And now? As I said, my face is now gently caressed by warm summer breezes. No buffeting, no grief... unless it's a windy day which makes for wind currents impossible to buffer.
Here's a pic with those homemade lowers. It's kinda hard to see but they extend from the bottom of the windshield right down to the fork seals.
I like it and it has a nice sparkle in the wings to go with the bling of the America's chrome!