The ones with the Dragons and Flames cut into them block the wind at that point and divert the air around them.
Some people use chaps instead of bolt-on lowers to help keep them warm and/or dry.
Thanks for all the info guys.
My main concern is the air coming up from beneath the windshield hitting me in the chest and causing helmet buffeting, not the cold/wet weather. (I live in South Texas)
Thanks for the tip, Xring, on cutting Lexan, I have a windshield I need to cut down. Someone attempted to cut a bigger hole for the headlight and musta done it with a pair of end nippers, very uneven. I have very limited experience cutting windshields and this will give me an experimenting point. Then I'll attempt to cut the top down about 3".