The main things are removing the cellular connection and disabling the connection back to the Tesla services. Back in the old days you could pull the SIM card, root the center and driver’s displays, setup firewall rules to block traffic to/from the Tesla servers, and disable the VPN.

This is more difficult with the newer models. You can still pull the SIM, but would need to get creative for root access since it is a continuous game of whack-a-mole between the root methods and patches.

Will certainly be a bummer if they do go under, I really appreciated their serviceability. Have several in the immediate family that have been going for over 7 years at this point though all kinds of calamities. Each time can I just pop out all the components clean/replace as necessary and get it back in service, good as new.