Put a GW style vent on my stock windshield. Very little benefit. The airstream thought the vent gets lifted up by the air over the top of the windshield so any idea that you get cooling on your torso is wrong. The concept of relieving back pressure behind the screen to reduce the turbulence didn't pan out either. Spent $30 and a couple hours then decided to buy the CB TRSSC which actually provided greater benefits.
Just thinking about it.....it would seem that a vented windshield might make sense on a taller screen that you look through, but would probably not make sense on a shorter flip-up windshield that you look over.
My Precious: 2011 Road Glide Custom 103 (vivid black) Performance Upgrades: V&H Dresser Duals, V&H Twin Slash Rounds, Screamin Eagle Air Cleaner, and DynoJet PCV Other Upgrades: 13" WindVest, PYMB 10", Hog Tunes, HD Chrome Grips, Streamliner Passenger Footboards, Kuryakyn Hwy Pegs Picture: http://i201.photobucket.com/albums/a...Cleftrear1.jpg