I can tell you first hand there is a good chance your RV was washed at one of those very Blue Beacon truck washes prior to it being delivered to the dealer.
Watch the decals...I have seen them blown clear off with a high pressure hose. The recommendation of keeping the nozzle 16 inches away from the rv is a good one.
1990 Jayco 250 Special
2008 Ram 5500 DRW 6.7, Cummins, Aisin auto
Holland/Binkley 5th wheel, Reese Dual Cam, and more
232,500 kms in 2013
200,000 kms in 2014
160,000 kms in 2015