Mexican License Plates and Stickers in the Window

When I would see a car with Mexican plates, I always noticed there was this sticker in the window that also had their plate number on it.

I never really understood the reasoning behind this. While I was at one of the POEs on my border trip, I decided to ask one of our TCO’s about it. He told me that many people like to just take the plates off registered vehicles and put them on unregistered vehicles in an attempt to make these vehicles look legit. Either these vehicles are imported and they are trying to avoid the tax, stolen so they can’t be registered, or people just didn’t want to go through the process of properly registering their vehicles. Now I knew a guy in Wisconsin who liked to do this. He had the impression that, if the plates themselves were valid and he put them on a vehicle, it was legal to drive the vehicle. He didn’t acknowledge the plates had to actually be associated with the vehicle. Well I guess Mexico has found a low tech way to prevent this. The sticker on the vehicles rips apart and makes it evident it has been tampered with. This makes it easy for a cop to verify the license plates without having to radio it in. I guess if Wisconsin, or anywhere in the US, followed Mexico’s lead on this, it might save the hassle of running the plates and they’d instantly know when the plates for the vehicle weren’t actually associated with that vehicle.