I have a LeBarron Bonney top on my Abone. It does flap quite a bit above 50mph. However, one thing that cuts that down tremendously is to open the back window flap. I don't know if yours has that capability or not. I also have separate rear quarter flaps that snap into place on the top and body that also helps prevent against the top flapping. I have the same problem with my windwings even at the correct angle.

Pat