Incidental rain is one thing, treating the bike like its more resistant to water than a submarine is asking for trouble. The HK radio is not waterproof, nor are many of the connectors or the gauges. Wheel bearings are routinely compromised by pressure washing.
Rain hurts very little. Pressurized water at odd angles creates water intrusion into sensitive areas and will cause you problems down the road.
I wrap a plastic bag around the A/C. I also, wear a jockstrap, since I'm an old geezer, & don't want my low hangers to come in contact with any sharp edges.