If you're at the end of the day, back at camp...I use a microfibre cloth, or an old wash cloth, mix up some warm water and hand soap....yup just a bar of soap...get the cloth really soapy and wash the inside and outside of the windshield.
Then take another similar cloth with just water and wash off the soap.
Then dry with a clean cloth.
The hot soapy water will just disolve bugs, mud and just about anything else on your windshield. The hot clear water rinses all the stuff off.
The dry cloth drys and buffs the windshield.
DId it on ElectraGlide fairing windshields for years, now RZR windshields and no problems at all.
Out on the trail...keep a small spray bottle of simple green and a couple of microfibre cloths. keep the cloths in a Ziplock to keep 'em clean and dry.
JMHO
Pirate