I'm a diesel mechanic by trade. for anyone curious to disable your cars data collection the OnStar systems easiest.

under your passenger dash is a black metal box, usually documented. unplugging the harness and removing it, you can open it to expose a baseboard and a riser. the baseboard is for things like infotainment usually but the riser is your cellular modem. pull it and you'll get a warning light on the dash, but no more data collection. older cars will have a Sim in the riser you can pull if thats less invasive to you.

note: OnStar is also disabled and will not dial 911/999 on collision.