Captain Bob on Aging Wheels bought some EV named for a stripper. I hadn't heard of it. I couldn't find any mention here,
so I mentioned it!
He was tired of the old worn-out walls, so he didn't sell it like J.R., he decided to cut 2x4s so he can install OSB over it, because he only does flammable and explosive things in there all of the time!
However, after cutting one 2x4 to fit he decided to give up 3.5" on each wall and nail studs to the steel crossmembers.
That left him with walls almost a foot thick and I thought "Those would allow for crazy insulation!"
He said that insulating it would be crazy, so he did!
He changed tools and techniques multiple times for multiple aspects, but he blew cellulose insulation into his almost foot-thick walls and then cut plugs with his CNC or something.
The walls don't go all of the way to the ceiling and he didn't add insulation to the ceiling, so he added a mini split instead!
Pioneer had given him some mini splits, but he wanted to try MrCool. He says that not only are they identical, undoubtably made in the same factory, but they are interoperable, although MrCool is slightly cheaper, available with free shipping on Amazon, and is easier to install.