I just did the map update to 12.5 for North America last weekend. The process includes entering the vehicle's VIN and the Device ID Number for the head unit installed in the vehicle.
From that, I'd assume that it's only going to work in one vehicle. If you copy everything over to a second SD card and try to load it into another vehicle it'll probably fail a validation check when the Device ID Number of the 2nd head unit doesn't match what's on the SD card.
I didn't review the files on the SD card to see if there was any way to overwrite the Device ID. You'd have to find where it's stored in all of the files to even try that, and even then there's a good chance that it's encrypted. All that said, it wouldn't surprise me that a more technically inclined person may be able to dig into things and get away with it.