For many RVers the end of the season is near so I thought I would revive this thread. Put ZEP on this Fall and next year you will not have to do any exterior maintenance.
My RV has been sitting unused since December. It is in a wooded area under some sort of fruit bearing tree. It looked horrible with lots of streaks from berry eating birds. I just washed it and it now looks like new. I had two streaks from berry droppings which did not wash off and are still visible. Otherwise it looks great. Without the ZEP I would still be working on it.