Not positive but I think all CR products have rubber roofs. I clean mine with a rubber roof cleaner (used to use spic n span but can't find it anymore). Some use a product called Solvit which I hear works well. After I clean the roof, I use black streak remover to clean the sides. If the roof is kept clean, you will get a lot less black streaks. Then I wash and wax the sides. Whew, I am tired already!
the PP has a rubber roof, and I use spic-n-span, the liquid, and I add a real small amount of bleach, keeps it nice and white, make sure you rinse it really good, I get the spic-n-span at walmart..