I just installed (4) 100 watt panels on our AF. All of them over the bedroom/cab over portion. There is room for another 3-4 farther back. Measure the available areas and have a look at what's available in those sizes. We also have a Bigfoot camper and looking on the roof there is more limited space due to the skylight over the bedroom. Panels come in different sizes and you might have to get creative and mix sizes to get 500 on the roof without racking up and covering vents etc.