The stryker will find or buy from somewhere, a pool of unissued VINs that don't flag anything in the state registration system and match various vehicles (Dodge Chargers, Kias, Hyundais). Then when someone comes with that vehicle, they will strike a new Vin plate. Sometimes if they buy the VINs it will come in a package with plates. From there it's possible to get the vehicle registered, most likely under someone else's name that has no idea and they will sell / rent the car with tag etc. Though sometimes they will just make a fake plate too and then steal a real plate, swap it with the fake plate and put the real plate on the stolen car and sell it like that. In some cases / states they can actually get a title reissued.
Boats are even better, but much smaller market, just look up coast guard plates on Amazon.
Stiker vs Styker, is regional.
For Reference: Striker Music https://www.youtube.com/watch?v=AaTxkD5JFpg