I’ve heard it can cause problems in some models, so people need to do their research. With my truck it’s dead easy and are no drawbacks.

We need an iFixit-like database giving each car a score about how easy it is to unplug the telematics units and what errors it may result in, complete with a score.

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!

Depends on the car but I'd say the chance is above 50%

Not small, but I think you’ll have better chances with the mid level commuter cars. You’ll probably get some error messages on some of them, but if you can ignore them, they wouldn’t stop the car from running.It’s the high end ones and EVs that have a higher chance of bricking if you disable the antenna.