I have some thoughts on making the same thing. Our AR190 will drip from the bimini directly onto the instrument panel in the rain. I want to shoot one of the Yamaha engineers for not making the top ~3in longer to avoid just that issue.
I had intentions of making some clear vinyl for the sides/front of our 190 this winter. Haven't gotten there though for a myriad of reasons. My intention was to add a zipper to the bimini top, and then some industrial Velcro, or snaps to the windshield frame to hold the bottom of it. Even a "3-sided" cover that was clear would be an improvement in the rain. You could keep your heading into the wind and keep the main cockpit area of the boat at least somewhat dry and shielded from the rain.
I know personally we aren't trying to boat in monsoons, or even stay out in the rain, however we will inevitably get caught in a squall a couple times a season. Spent 3hrs in the rain, and the dark last September waiting on the locks to get back up the Cumberland river into Old Hickory Lake. Would've been really nice to have had a wind/rain break at that point.
@Julian made some nice vinyl windows for his outdoor patio/deck in
this thread. I was going to follow his lead for the boat. SailRite has some EXCELLENT videos on how to make curtains/windows/panels for your boat.
Here is one on Side Curtains.