When I got back from the Flathead Valley, the front of the coach was just a mass (or mess) of splattered bugs.
wishing to have the least amount of work getting it clean, I decided to use windshield washer fluid, full strength, in a garden sprayer. I had a gallon jug of the cheap stuff, so I liberally sprayed the front of the coach with it, waited a few minutes, sprayed again, then washed it with a brush that attaches to a hose, so water is running through the brush at all times.
The coating of bugs just pretty much rinsed away! Windshield or fiberglas, didn't matter, they mostly just rinsed off! There were a couple spots that needed to be scrubbed with the brush, but all in all it was the easiest bug clean I have ever done!
DW got back from Thermopolis, WY on Monday, very few bugs on the front of the coach. Either there were no bugs in WY, or they just didn't stick. Whatever, the front of the coach is pretty clean.