Until then, OTA radio will be omnipresent and free, and internet radio will be subject to wifi availability, and will be limited by bandwidth costs.
Not really. A good many people now readily pay for mobile data on their cellphones. With newer vehicles, your car's audio system can connect your phone via bluetooth or tether.
I just bought a 2015. It's not a Bentley. It's an economy car. It's a base model. It's dashboard has a screen, and when my phone is bluetoothed-in, I can access not only music saved on my phone, but it can pipe through a streaming service. It even has a Pandora app on the screen that accesses Pandora on my phone. It plays the music and gives me title/artist/album info on the screen, all making use of my phone's connectivity.
Local broadcasters wanting to survive in this new world need to find a way to have their stations pop up on my car's screen next to Pandora. Whether the car pulls in the audio via a broadcast signal or a data stream doesn't matter to the listener.