How about a fiberglass rod , about the thickness of a fishing pole or tent
pole,and about 10 or 12 feet long.Fasten this to each end of the rain
gutters on the rear of the vanagon,making a hoop big enough to take a
shower in.Hang a shower curtin(decorated with pink flamingos, of course)on
this rod.2 gallon milk jugs of water that you dump on yourself will do the
job.If you have any water left over, clean off the soap that got on the
vanagon.Either this or just do it behind a rock or down in the woods.