What still functions and what broke?
Also even with no modem, if you use CarPlay on your phone _via Bluetooth_ then the car will just use your phone's internet connection, so I only use CarPlay via a wired USB connection.
Aside from that the car works great, everything is 100% functional. I suppose I don't get OTA updates, which I'm fine with.
Wouldn't that also share your phones internet connection with the car?