You can do this with a Tesla of course; either disable remote access (leaving open firmware updates and traffic analysis to the mothership) or remove the Wi-Fi and cellular antennas. While a bit involved, it is entirely possible and will leave you with a perfectly "working" Tesla.

The car doesn't require connectivity. Although it sure is nice being able to pre-heat or pre-cool your car before you go drive it.

There are also jailbreak options for Teslas.. you too can run a virtual machine inside of your entertainment computer.