I like knowing that it was clean before I left home and it doesn't matter what it looks like when I get there. If it's real bad,I'll wash it as soon as I get home and if it's not, I'll clean the bugs off the front. It'll get washed before I head out again. In the winter,that's a different story,especially this winter. Even though the weather was pretty good this fall here in the beautiful PNW, for some reason the cedar and fir tree I'm parked under have shed a lot and when the rain hits,it causes major black streaks and moss when it runs off the roof. I've taken it out for a freeway run several times to blow the stuff off the roof as it really got thick. I have a PVC roof that has never had black streaks till this year.
I'm heading to the RV shop this week to get my icemaker rehooked after they replaced the cooling unit last week and I'll hose off the roof and wash the green stuff off the outside. Then next week I'm heading for Portland and Astoria and I'll check it before I go and it'll be washed when I come back.