I have not purchased a TV or car with these misfeatures, but I expect I will have to at some point in the future.

The most vulnerable part might be the antenna? Required by laws of physics to be a certain size and shape, and is not easily integrated into another more essential component?

If found, it can be removed entirely, or replaced with a dummy load to satisfy any presence detection circuits. But radiation can be minimized or eliminated.

Now obviously a device can choose not to function (or to be especially annoying in its UI) if it doesn't find a network. But people take cars (and TVs) to places with no WiFi or mobile coverage, and I don't know how the device manufacturers deal with that.