Oh yeah...go to my blog at
http://billnjudi.blogspot.com/
first pic that comes up is the one I just built.
2x4 frame, complete with 36" door, carpet and sat tv. Doesn't fasten to the rig at all. Built 2 sidewalls and front wall, elevated rig a little bit above level, slide in walls and fasten to each other, put 1/2 pipe foam insulation around top, lowered rig bad down to hold in place, then built the short section that goes down by landing gear. Has withstood 45 mph winds so far with no issues.