Every once in awhile, a product (or two) comes along that just makes sense. Such is the case with GoStik Products.
I recently purchased their flagpole mount as well as their towel bar. These products utilize a suction cup made by FastCap called Handle on Demand that is typically used to transport glass panels and other such items.
Depending on the model, these handles can hold 100lbs to 200lbs, which is more than sufficient to hold a flagpole or towel bar.
These handles work so well that I have found a couple additional applications for them - including the attachment of a weather sensor to the RV, which includes an anemometer, wind vane, rain gauge, hygrometer, and thermometer.
Towel Bar Video.