I"m no longer a member on the K1600 forum, but perhaps Berber can search that forum for us if he reads this thread and find the comments on products for this purpose. I do remember that some are specifically NOT approved for use on plastics, I just don't remember which ones. The issue as I recall is that some of the compounds cause aging or yellowing of plastic windscreens and visors depending on the type of plastic material. I'll look around to see if there is something specific about it. I never use anything but soap and water wash and Plexus if the windshield is dry, but Cal Sci has a homemade cleaner recipe for their windshield that works OK and is cheap to make. Plexus has gotten very expensive - ouch! Most motorcycle windshields are made from GE Lexan (which has been sold off to a Saudi Arabian company), and some are made from acrylic (which is not DOT approved in the US for windshields unless it is impact modified) which is easily shattered.
From the Cal-Sci website for cleaning their impact modified acrylic windshields:
Makes 1 quart = 1 liter windshield washing fluid
1/2 cup = 100ml ammonia (double this if you have a lot of bugs)
2 cups = 400ml isopropyl (rubbing) alcohol
1.5 tsp = 8ml car wash detergent (don't substitute dish soap or laundry detergent)
2 cups = 500ml water
We recommend using only micro-fiber cleaning towels on your windshield.
If you don't want to play home chemist, go to WalMart and buy a gallon of Peak Windshield Cleaner (blue), about $1, and a gallon of Peak Bug Remover / RainX (green), about $1.50. Mix them 50-50 and use that on your motorcycle and in your car.
Lexan is used by some mfr's due to it's durability, but usually is only made by people that make plastic due to the complications with removing the water content from it before putting a coating on it for windshield use. Do not use ammonia cleaners on Lexan!
HOPE this helps some. If not there is plenty of info out there on the internet of things.
