When reading the article I think he appears to be talking about car play/android auto connection not audio only connections. I think Bluetooth in AA and Carplay is used to configure a local network between the phone and the car to transmit the images to the cars screen. I would assume that that data capability can also be used for the car to communicate with the Internet.
Does anyone have a flow log or pcap or something from the phone showing this tho?
It does produce a local Wi-Fi network but there's no evidence that it supports internet communication. That would be considered a hotspot, which not all carriers even support.