I added an outdoor shower to the 6 X 10.
It's made using common hardware. The curtain rod is of bent 1/2" conduit that clicks into conduit sockets that are mounted in a couple of hasps, the bar being held in the socket ends using spring buttons.
The hasps are for safety should the bar be forcefully pulled down and they have pieces of plastic spoon handle that will shatter and release the bar to swing harmlessly down before the trailer wall would be damaged. I tried to use rare earth magnets for the breakaway but just couldn't get a strong enough arrangement with the space for leverage and the materials that were available.
There are rare earth button magnets sewn into the curtain so that on the 'window' side the shower curtain gloms on to the vertical steel wall brace running down just beside the window, Another magnet on the other side of the shower curtain at the top attaches to the steel behind the aluminum skin above the door, when the curtain is closed.
The door can be partially opened enough for the bather to get out, and it just raises the curtain a bit on that side, which falls back into place once the door is closed again. Or one can shower with the door open, water doesn't seem to get inside. One can enter and exit without being visible from outside.
That 12 volt shower pump setup is sold on eBay for $20.00! Works just fine. There's an electrical switch near the shower head and outside the trailer so you can shut the flow off to conserve water while soaping up or shampooing. Biodegradable 'camp soap' of course, because it's just falling to the ground and running off the shower mat. The soap caddy hangs inside normally, easy to move to the outside hook.
Water is heated in the all purpose stock pot. It takes about 15 minutes to heat a 2/3 full pot that's good for a nearly 5 minute shower.
You start the water heating while setting the shower up. Poke the 12 volt plug and the pump through the access door from outside (the shower head is too big for this), hang the lines on their hooks, and plug it in. The pump dangles from that hook on the microwave shelf above the stove, so that it barely touches the bottom of the stock pot. The shower curtain rings are held with a velcro strap when not in use so that you don't have to thread each one each time you hang the curtain, just poke the rod through all of them at once and then take the strap off.
The curtain fitted shower rod, normally stored inside on clips around one window, is then pushed into the sockets while squeezing the buttons in, and the shower curtain is attached to the outside wall via the magnets.
The heat is turned off once the water is the desired temperature, and voila, shower.
No adjusting to get just the right temperature, all the water is the exact temperature you wanted right away.
The pump and shower stuff stores in the stock pot under the oven when not in use, the shower curtain gets draped over a bar on the inner door surface.
When set up but not in service the curtain can be held open by the one extra long cloth strap on a middle magnet pocket that wraps around from the inside and goes back under its magnet to hold the shower curtain open like a sash. Then the privacy curtain can also be used for a porta pottie, that sits in front of the wheel well.
Now I just have to come up with some sort of toaster cover type cover for the porta pottie, so that it looks a bit more... elegant sitting there.