RE: Shower Schemes
Easier than toting a fiberglass tent pole around:
That tarp you always carry (don't we?) can be draped across the raised rear 
hatch, solar shower placed on top. Lines or clamps to hold the tarp in 
place, piece of PVC pipe on the strut to keep the hatch open. Even a place 
to lay your clothes, towel, soap, etc. in the back of the van.