Look into Fiamma racks.
I took a serious look at them and still may buy one.
They bolt onto the back wall of the RV.
You would probably need to find the wall studs for attachment though.
They use them all over Europe on their smaller B and C RV's and they are starting to pop up here in the states.
I saw one on a new Ford class B and they are slick.
Fold up when not in use.
The frame stays attached to the wall.
I think the manufacturers should offer them as an option.
No more hitch mounting.
VW Bike Carriers, Panel Van Bike Racks, Tailgate Bike Rack