> then the car will use your phone as an internet connection and send all the same telemetry data back to Toyota [...] so I exclusively use CarPlay via USB.

I would be concerned that a passenger connecting their phone to it while I was driving.

In other cars I've been successful picking up the relevant modules for peanuts from surplus/scrap then just desoldering the RF-active components (like bt radios, etc) and swapping them in. YMMV but if it doesn't work you're just out the cost of a junk part.

Even if some radio feature is benign its existence means that its hard to be confident that there isn't some other telemetry feature you missed. With no connectivity at all you don't need to worry that you missed something because you can monitor the car with a spectrum analyzer and observe its never transmitting.

Unfortunately in some newer cars you can't swap any modules without a dealer tool to pair the module to the car, presumably in a bid to prevent third parties from fixing the car (presumably preventing people from lobotomizing their surveillance isn't on their radar yet).