Can ISP’s really flash firmware to a 3rd party router? That’s wild. I’m not sure that’s happened to me before, and I’ve been forced to use Comcast/xfinity my whole adult life. I’ve had multiple Arris modems, and whenever I check their status page, it was always Arris branded, and stayed the same before and after hooking it up and registering it with the ISP.
I always assumed the rigamarole of registering a personal modem was simply a white listing process (give MAC address, receive internet). I’ll have to look more into it, I didn’t know there was anything else going on.
My suggestion, if you’re looking for a new car, is to research where the modem in the car is, and unplug it during the test drive (assuming it’s reachable).
I unplugged the one in my work truck, 2023 Ford F150. They call it the “Telematics unit” and it’s on the rear cab wall on the right side, hidden behind the sound deadening foam. I did this after it was bought, but if I had known about it before my boss paid it, I definately would have tried it before the test drive to make sure, and I plan to do it if/when I look for a newer car!
I unplugged every cable coming into it - power, antennas, data, all of them! The only issue that comes up is the center screen on the dash crashes back to the main menu when you try to open the data/wifi settings.
No other issues so far after almost 5k miles! No warnings, no lights on the dash, nothing! Android auto/carplay even still works! Don’t know yet if the dealer will try to plug the unit back in during the next service, but I intend to raise hell if they try!