CJW8 wrote:
In my case with two large panels mounted lengthwise,one behind the other, behind one of my air conditioners, I think there is very little chance of wind lifting them off.
Same layout on my rig. 2*250W lengthwise, one in front and one behind the A/C. Both are along the right side. The roof of my trailer, and vast majority of other, is crowned, so the panels conform to the slope of the roof. This reduces the windage and provides necessary slope on the panel for water shedding.
Correction/comment on SMK install - his are 225W, not 250, they look like more "square-ish" in shape.
The discussion would've been more productive if the OP posted the details on where exactly his 6x8ft clear area is. If it's 8ft across and 6ft lengthwise, 2*250 won't fit in the same way as SMK's. He'll likely have to mount them separately on left and right side, conforming to the roof slope.
Salvo - I hear you on "not if but when". But... if it's going to take longer than me or my trailer will last, who cares :)