Open source cars are kind of a thing, if you're doing an engine swap, or building from scratch or something, that will usually require you to remove all of the privacy violating parts as a side effect. You could probably achieve a similar result with slightly less effort by removing the infotainment and replacing the ECU with an aftermarket one...
Most of the privacy violation parts are just in the infotainment though, so if you manage to replace that you'll be pretty much there. Only issue is newer cars have all the hvac and things like reverse cameras controlled through it...
Another option would just be to make sure it has no network connections.