Cars are a ‘privacy nightmare on wheels’. Here’s how they get away with collecting and sharing your data::Cars with internet-connected features are fast becoming all-seeing data-harvesting machines—a so-called “privacy nightmare on wheels,” according to US-based research conducted by the Mozilla Foundation.
Countering this is very make-specific and you can have options ranging from calling in (opt-out) to pulling fuses to messing with dash wiring.
Make/Vehicle-specific forums will likely be a good resource to start with but naturally you’ll have to deal with the “you have phone, lul” defeatist idiots anywhere.
Considerations include age (Models with 3G radios are disconnected anyway most likely), trim (maybe only certain trim levels got a cellular radio), and features. (Hotspot, OnStar, an SOS button indicate the presence of such a telematics system)