I use a 1/4 cup of hydrogen peroxide mixed with distilled water in a spray bottle, The peroxide reacts with the proteins in the bugs and softens them up. They wipe right off with a micro fiber cloth after a minute or two. It works great on the fairing as well. I finish the windshield with a good ammonia free cleaner such as Invisible Glass. Then I follow up with a good quick detail spray, I like Renny Doyle Bead Maker or Bug Slide.