There are satellite Internet products for vehicles, but they're kinda big. For instance, the Raysat Stealthray 5000 is 45x35x7.5 inches. Basically they're made to go on the roof rack of a SUV. They're also 80 pounds. Oh, and VSAT service is really expensive.
The truth is, since 4G came out, the cell carriers have determined there isn't money to be had in minutes or even texts anymore. The future in billing customers for cell use is in data. For this reason, many of us had Unlimited data previously and subsequently lost it during an equipment upgrade. Many of us lost our 5GB plans in favor of 2GB for the same money.
I've built Broadband wireless infrastructure in the past. It takes a lot of work to deliver streaming media, especially in real-time, to a dozen cell customers in the same cell at the same time. The cell carriers dislike these customers and aren't going to build for them. If it works, great, if not, oh well.
There are some tricks to be had, like LTE Broadcast (Multicast) and the like. Unless a cell carrier is suddenly going to become a strong content provider, I don't see this being a heavily invested thing in the immediate future.
The reason why I think ditching AM/FM radio is not terribly likely is because it's really trivial and cheap to implement. If you were going to ditch anything, you'd ditch the WiFi Hotspot technology that most people wouldn't subscribe to because it is expensive to use. Instead, you'd have a connection to a customer cell phone, which is cheaper and they're likely to at least use it for advanced telematics.