[rotaxman]

David,

You might try Murphy's oil soap it was the only thing that Doubletree at the time recommended for the vinyl roofs that they were using on the 06 units.

I have used it on this junk 09 as well but it does have a rubber roof. It does a pretty good job for stubborn spots if you use it full strength.

I usually mix it with water I don't have an exact formula I just mix it until I get a real soapy mixture. It does a pretty good job but I can tell you it takes a lot of work to get a roof looking good.

I scrub it with a fairly stiff bristle brush I use a gardening pad as I'm on my hands and knees and its a long day by the time you get it all done.

Let me know how it works.

As always good camping
Joyce and Jerry