We do….we have an outside shower on our TT and park the truck beside it to block the view, but also I bought a tension shower rod and shower curtain (not see thru!) and put it up between the 2 slides where the shower is. Works like a charm! We also have a rubber mat for standing on. Saves on grey tank storage for sure.
Another trick we discovered was showering inside where we dump our tanks! We go to the dump station, dump the 2 tanks, fill the water, pull over out of the way, shower and then dump again. That way we start out fresh and clean with empty waste tanks and a full fresh water tank, and clean bodies! With 3 of us in the TT this makes a huge difference.
I know from reading and listening to others who full time with converted van and autos that they do shower outside inside of a tent or tarps wrapped around to0 make a shower stall. I have to admit I never knew so many did shower outside. But it does sound like a great idea and save space in the tanks.