Over-the-enclosure-wall Towel Rack

Go get one of those 16x16mm (5/8 inch) rounded-square hollow towel bar things from your hardware store, and shove these onto the ends, and you now have an extra towel rack for the outside of your shower enclosure, or wet rack for the inside for washcloths, bathing suits, etc. Make sure your shower wall is at least 3cm wide at the top so you know this will fit.

Those named "glass" have a longer bottom stick (by 10mm) on the assumption that your frame at the top is a little wider than the glass