I'm reminded of the British weather when I think about this... I donno, brolly with various arnie designs? I know it'll end up being awkward or complicated to out-sourse or contract somebody to make or arrange, but it's an idea.
Brit weather right? or random things for the car, so if you're picking up or dropping off mates that skirmish (or not) but don't use arnie's... they'll see that (hopefully)
Again, my imagination takes things a bit far, but what about figurines that replicate the current cartoon design of "arnie"?
keyrings/fobs, wallets, phone straps... designs may vary,