I had one situation in very heavy rain where the fairbourne screen couldn't shed the rain fast enough, I had to look around the side and depend on my helmet visor to see, at a very slow speed. 2 lane road, no shoulder to pull over onto. Rain let up again after 5 or 6 minutes.
I sealed the front bottom edges of mine using the masking tape method, and a popsicle stick. Worked very well.
