I'm happy to help just for the love of the game.

The data is transmitted via a radio signal of some kind. That radio signal is created by a transmitter. Stopping the data transmission is a matter of finding and destroying the transmitter or its ability to operate.

The exact "how" depends on the make and model, but in general, removing or destroying the antenna is probably going to be the easiest way, but this usually results in destroying all the radios in the car. You'd probably still have Bluetooth, aux, CD, tape, whatever, but AM/FM, satellite, OnStar, and similar would probably be broken also.

If you don't care about concequences, you can do that yourself with an angle grinder in a few minutes. Hopefully you don't create any leaks you can't fix with a tube of blue RTV (yes, color matters, blue is for marine/water).

If you're determined to keep the other radios working, you would need to do some research to determine how your specific model "phones home". Most commonly, this is via 3G, but other solutions exist. From there, it's a matter of destroying, removing, or short-circuiting whatever component controls that radio.

I pulled the fuse on my car's DCM. Cost me a speaker that is on the same fuse, and of course Bluetooth etc, but I don't care about that. No check engine lights, easy to reverse if needed. But this depends on each model of car.

Sniff for mobile network radio signals. And keep pulling things out till that stop, then keep putting things back till the car starts working as expected. Simple as bruv /s