Modern cars are computers on wheels - they have more sensors than you can count and are constantly phoning home with telemetry data like your location, speed, fuel levels, sudden accelerations/decelerations, video footage, driver attention data from eye monitoring systems, and hundreds of other data points. Cars have inward- and outward-facing cameras. They have microphones. They have always-on modems. It’s all enabled by default with difficult or meaningless opt-outs, and your data is monetized through brokers like LexisNexis or Verisk.
I would like to do this to my car, I’ll save this and see if others have done it for mine.
Some cars have the cellular modem (often called the “telematics module”) on a separate fuse. Just pull that and you’re good to go without doing any complex disassembly.