FWIW, for years we have been using white colored small diameter spring loaded rods (available from Camping World and other sources) of various lengths in several places in our RV. They're not shower rods ... they're too short and too small a diameter for that.
We use them in the RV's refrigerator door shelves and in various other coach cabinet shelves to keep stuff better organized and from falling out.
In each rod, if you screw the one part in/out from the other part you can set the amount of force applied by their internal spring mechanism to hold them in place.
Overall, they're an ingenious invention and especially useful in an RV!
