Here's the one I use. Old 12ft Surf rod that shrunk a foot going under a carport once...... but thats another story....... Aussie flag is cable tied on and the sand flag above is held with Loctite. The rod wedges neatly into the bar and is secured with a couple of cable ties into the uprights, where i drilled 2 4mm holes.
PS, I have a roll of the material they use for the sand flags so when one dies I just cut another and glue it on. Happy to flick some to you when you are next up