Ok, before we went to Florida this spring, I bought one of those stick-on tri-flag holders. The holders are sold at Camping World and Campers Choice ... and probably your local bubbas rv supply house.
I wanted to make sure that the stick-on flag holder withstood the test of time (and wind) before I posted something about it.
I mean, the thingie has three little suction cups, so you just slap it into place anywhere on the outside of your smooth molded fiberglass rig ... so I thought that the combination of a strong wind and flapping flags would pull it right off the trailer.
I was wrong. That little sucker has stayed stuck through some really high winds ... and aside from one of the three suction cups occasionally coming unstuck, has never fallen off the well waxed rig.
It works great ... and we proudly fly two American Flags (with the possibility of adding a Prince Edward Island flag later) ... whenever we stop for more than a night or two.
Here's the link to the item at Camping World: