Finally got the last panel bolted down this weekend and everthing's charging. Six panels up top, wired in pairs to a single gland box on the back corner of the roof. Took me way longer than I planned because of all the stuff up there - two AC units, three vents, a skylight, and the antenna all had to be worked around. If I did it again I'd map out every obstruction with actual measurements before ordering panels.
Biggest tip: mount panels at the very edges where posible. Keeps them clear of the middle clutter and makes walking on the roof way less awkward. Also, run all your wiring through the gland box in one spot instead of drilling multiple holes. One entry point means one thing to seal and re-check later.
Use butyl tape under every mount foot, then screws, then more sealant on top. I skipped that on my first trailer years ago and chased a leak for two seasons. Also dry-fit the whole layout with painter's tape before drilling anything. Sounds obvious but I skipped it and ended up shifting one panel four inches after the first hole was alredy drilled.
For the wires themselves, leave slack at each panel. Roofs flex, panels expand in the heat, and a tight run will eventually rub on an edge somewhere. Zip tie everything down so nothing flaps, then check the whole run once more before you seal up.