I drove from New York to Ohio to Toronto to New York. And I was nailed with this in Ohio before I got to Toronto.
I was ticketed in Columbus, Ohio - of all places. I was literally walking to my car after making a business call. Car was parked at a city meter. Meter Checker was writing a ticket. I said, "What's going on? The meter has plenty of time left?"
Checker said, "Your tag is expired".
I said, "Nope, I renewed it but forgot to put the sticker on. Here (reaching into my glove box), Here is the Sticker!"
Checker said, "It has to be prominently displayed on the Plate"
I pull off the backing, and past it on the plate. I say, "There, it's displayed".
Meter Checker hands me the ticket and says, "It was not displayed when I wrote the ticket. Have a nice day"
Oh well, he probably saved me from getting two or three tickets in Toronto.