i use the harley sunwash for doin the whole bike. less waterspotting than conventional car washes. seems to do a good job on the bugs. however if you are just looking to clean the windshield use novus #1 windshield cleaner and polish. can be had for less than 4 bucks from yer dealer. use a soft cloth and buff till clean. works swell i swear!!
I use an old towel soaked with hot water + Ivory liquid. Lay it on over the windshield then wash the rest of your ride. When your done, pull off the towel and rinse. The soapy towel soak really removes (or at least greatly loosens) the bug death.
Some dish soaps can actually fog the windshield permanantly, but the hot water and towell works great, but then again riding in the rain works great for getting rid of the dead bugs on your windshield.
I also use novus and plexus, both are good. They have a special oil compound that does not scratch the windshield over repeated cleanings. If you just use soap and detergent then I promise you that you will have small scratches on the windshield that cannot be removed. After three years and 20,000 miles my windshield looks brand new.
PS: plexus is used on the cockpit plexiglass of f-15 aircraft for the same reason....
You can try a dryer sheet, like Bounce ......... wet the area first, then wipe, not rub. Keep the area wet as you wipe it with the sheet and the bugs will just fall off, works very well with Love Bugs and the like. Laugh if you want, I did, but give it a try, you'll be amazed.
I mix a 50-50% solution of Hydrogen Peroxide and water in a spray bottle. Spray it on a watch them bubble off. I leave it for a few minutes then rinse off with wet micro fiber towel.
HP turns to water after interacting with the air.
This works good for the rest of the bike also.
Here is TX we get the Grasshopper season in mid summer and the back roads are covered.
Don't mix more than you will use cause it goes to waste after a short time unless you keep it in a brown bottle.
Try it you'll love it.
Also have a case of Original Bike Spirits (used to be called Honda Wax). You can spray it on the windshield and let it foam up for a minute or two then hit with Micro Fiber cloth. This stuff works great for the rest of the bike also for a quick detail.