From the start of my build, I always planned to paint the top surfaces with a reflective aluminum paint, to diminish the sun's heating of the cabin. I was going to get a urethane coating called Aluthane,
but the price was sorta high, and one trailer builder said he didn't like the results he had. The specs looked good, but I didn't want to chance a higher-priced coating with mixed results. I was also going to use a Valspar-made farm implement paint for tractors, sold at Tractor Supply Co., for the sides, and while shopping them, I spotted another Valspar-made paint...aluminum heavy duty (for silos, barns, etc.).
At 1/3 the price, I bought it, and eventually used it. I used a (very lint-ridden) roller, and wasn't pleased with the results. It didn't fade nor rub away in the year it sat in my garage, but I re-did the front and rear panels with a brush, with better results. I can't report on the effectiveness of the reflectivity, since it is always in the shade (in my garage at home, or under an Easy-Up at camp. But, even so, I'd use it again. Also, Tractor Supply now uses Majic-branded paints...I don't know if its the same formulation now.