I have eliminated head buffeting by adding fork deflectors and a device called a laminar lip to the wind screen. The lip is a reverse wing that forces the jet stream about 4 inches higher over the windscreen without it. Im 5'9" and its enough to keep my helmet out of the wind blast over the top of the windscreen. Between the two my Interstate is a dream above 55 mph. Heres pics of them. The fork deflectors I shaped myself because I felt the originals were too large. I really feel the fork deflectors solves 75% of the problem.
sorry i posted my last message under the wrong topic. Apologies..