While this method is certainly quicker, and may be fine for a smaller F4, my +9 wiggles a fair amount at slightly greater than highway speeds with various cross breezes. I'd be reluctant to use tape and plastic body clips.
I also have the F4+9 and have not had any appreciable wiggle. I do have the Twist Dynamics roof and perhaps that helps deflect the air preventing the wiggle. Mine was one of the first +9's and I do not know if they made any production changes to them later on.