When I bought my previous XTZ, it had a Touratech high screen fitted. This was a disaster and I experienced chronic buffeting. I replaced it with the OEM screen and the buffeting went away. I'm 6'2" (1.87m) and I put it down to simply having the head(helmet) in the wrong place or wrong height. In my case the taller screen left my head right in the burble. The helmet needs air, it just needs clean air and to be rid of that dreaded burble. I would start with a shorter screen and work up from there as suggested about (hacksaw man!)