Seems you people need a lesson in forward thinking here
Put said platform at front of van, clean first part of roof, jump off said platform engaging in a forward roll, switch on motor mover, drive van forward, jump back up on said platform, repeat exercise until the whole roof is cleaned.
Oh sorry you will then have to pick up and move said platform to other side of van and again repeat all steps above :evil: :evil: :evil:
Or you could do as I do, step ladder inside caravan open Haki roof, climb on roof, wash and polish...done.
(Except I havent been up there this year!!!!!!!!!!!!!)