WOW! That was an impressive video.
Rest assured, when in the area, NIRV will be a "stop" & will avail the coach to a wash job like that!
It takes me roughly all day, about 8 hours to do what they did! And as I get older, that climb onto the roof, & moving around on it, becomes a bigger & bigger challenge! That job is for you youngsters, 65 & under!