But I don't want an old car. Old cars suck. I want a new car with all the self-driving stuff and without the tracking. :)

Then take an open source car and merge your changes.

Tesla is like the Apple of the EV world. Chinese EVs are like Androids.

I've heard of people pulling the cell modem off their car. You could probably replace it with the calyx os WiFi modem/router and then try and boot a Linux distro on the cars computer, utilizing the link I posted in these comments to access software necessary for your cars operation

This will be a tough one. Especially with self-drive mode. I'm not sure if regulators would allow #openSource self driving cars. Ok maybe in Texas but definitely not elsewhere. And I'm pretty sure Europe will never see such cars. We already have problems getting cheap Chinese EVs.