If you leave your car music source as your phone (connected via bluetooth), you can just use the TuneIn app on your phone. Seems like this would be very easy vs having to reconnect the car wifi tether when you drive.
Maybe it’s just me, but I’ve not found the Bluetooth audio quality to be very good. Perhaps it’s because the speakers are so much better that I notice it more in this car than my old car, but Spotify streaming directly vs Spotify streaming over Bluetooth is quite different!