One of the headaches that I have faced since moving to the Darkside that I never had so much trouble with on the Pup is the black streaks. My TT has the aluminum siding and a large "garage" door on the back similar to the small access doors. While the TT looked white, I could see the black streaks from afar but when you got up close the whole thing was, well, dingey. No amount of washing would remove it, Mean Green, Citrus Purple Power, even the Super Clean Degreaser didn't cut it. While searching solutions on another RV forum I found "LA's Totally Awesome" was recommend and carried at the local "Dollar General". It's also sold a Dollar Tree, Walmarts, and Amazon. http://www.dollartree.com/assets/product_images/styles/large/152664.jpg Sure enough, this stuff WORKS! At first I tested it full strength,and nothice it was turning white so I was worried about the paint. It was probably just the oxidized layer coming off but found diluting it 25% with water didn't make a much difference in how well it cleaned which was AMAZING!