First of all, welcome aboard and congratulations on purchasing the best ride on the road.
I knew there was something so I had to go outside and take a look for you.
Look at the grab rings near the rear side windows. On the outboard side of the ring near the glass, you'll see a small "finger" stiking up. this was intended as you clothes hanger. As far as mounting a clothes bar, I would venture to believe that since the grab rings are mounted to the pillars and not the doors, you could put some form of bar between these two rings supported by the two rings.
Jamie