Even though I live in Canada, it seems to me that every U-Haul truck I see has Arizona license plates. Even ones with obvious Canadian decals on the side! While I’m sure that there are some with other license plates, is there a reason for such a high percentage of Arizona plates on them?
They’re all built - or heavily modified - in PHX, Arizona, where Uhaul’s corporate headquarters are. I assume that they’re all licensed there for that reason.
I believe all U-Haul vehicles are licensed in the state where the individual franchise-owner is, so an Illinois franchise-owner would have all his original vehicle inventory licensed in Illinois. Then someone rents those and hauls them to, say, Florida or Tennessee, and leaves them with another U-Haul franchise-owner at the other end, in Florida or Tennessee. The U-Haul franchises all have some kind of reciprocal agreement to maintain the vehicles that are on their lot, whether they’re “theirs” or not. That’s how the whole U-Haul system works–one-way rental, you leave it at the other end.
This means that you can go to a U-Haul dealer in Illinois and see U-Hauls with license plates from all over, because someone just brought them in from wherever.
The only reason I can think of that you would be seeing lots of Arizona plates in Ontario would be that lots of people were renting U-Hauls from an original franchisee in Arizona and hauling them to Ontario. This doesn’t seem likely to me, barring some great mass migration of people, so I’d have to question the validity of your observation, albeit hopefully in a non-confrontational manner. 
Isn’t it more likely that once you formulated the thought, “Hey, it sure seems like you see a lot of Arizona plates on U-Hauls”, then you started remembering the Arizona plates you saw, but you’re just not remembering the other plates?
We rented a U-Haul this summer. In Ontario. It was from Arizona.
OK Here we go again…(wife managed a U-haul store here in San Antonio)…U-haul is based in Pheonix AZ. The insurance rates for fleet vehicles is lower ther than most states. Also since the final assembly is done in AZ. Maybe the liscensing and tax rates may be lower? Trucks are NOT owned by individual franchisees. They are actually assigned to the dealer/centers for rentals. In the past the trucks were just liscensed in the state that they were assigned to…But the discepancy of prices made it logical to use a fleet price made it logical to pay one price for every truck. Soon all U-haul trucks will have Arizona plates, but they can still operate all over the continent legally…
Sorry didn’t mean to be smart ass… Here we go again meant here we go another long explanation from me…(dang I do that a lot!!)
Another point I may have missed You might run into some problems in the south end of our continent…
Meant to say north america…