It should be possible to physically disable the cellular modem in the vehicle, wherever that is. I have a 2020 Volvo that is definitely online, waiting for me to activate some pricey online subscription that I don't want or need.
Would be nice to have a organized online database of how to disconnect various "smart" devices— cars, TVs, appliances, etc.
In my VW, the cellular modem and something I actually use (I think it's the Bluetooth microphone) are in the same module, so pulling the fuse or disabling it in the CAN gateway would be too heavy-handed. I would need to spend hours getting to, and into, the module. Or maybe replace the antenna with an effective dummy load / terminator? Tons of trim work. Luckily it's old enough to be 2G, and my understanding is most towers no longer speak to it, so I haven't pursued it further.
We tolerated worse gas mileage (computer controlled fuel injection, transmission, etc.), safety (anti-lock brakes), etc. We added computers because we wanted to lessen the effects of climate change and keep more people alive.
You're using a broad definition of "computer".
We've had these features for decades now, until recently the logic was handled by microcontrollers. It's not clear that the functionality requires computing devices also capable of data gathering, storage and upload.
Not really. Personal vehicles are responsible for such miniscule portion of co2 emissions it barely matters.
Emission regulations enjoy popular support because of city air quality, not climate change. Yes, people tolerate taxes on CO2 emitted by their vehicles (do you have that in the US BTW?) because it has a very beneficial side effect of also limiting particulates and NOx CO and such emissions that actually killed hundreds of people every year in major city centers. Also caused lifelong disability for many children(asthma).
Would be nice to have a organized online database of how to disconnect various "smart" devices— cars, TVs, appliances, etc.