How do you wash your camper?

It might sound like a stupid question. Since our current camper has dark full body paint I can't use our home well water. Too many minerals and it leaves a ton of spots and a haze. No matter if I disconnect the water softener or not.

What I do now is use about 7 gallons of well water ( fill a pail twice) and vinegar. I have a squeegee with a sponge on one side. Dip in the water and then squeegee off. Actually it looks great when done.

I wish I could wash with the water and soap & wax concentrate, but it looks like crap. Anyone else have this problem?