The one at the back is on a strong telescopic rod (think it's a shower one and has a very strong spring in it). Though after I had got it I did think that another way would be to support a more normal rod on two hooks screwed into the the end of the overhead lockers at the foot of the bed. It's also useful to hang lightweight towels on during the day to air.
I think most pvc will suffer from rear door draughts when we had one I fitted a flap top to bottom of the center jointThanks. I dont think we're as handy as you. But clearly the van needs some kind of insulating curtaining.