Can you connect a radio SDR key to the CarPlay 2 Droid?
@dauchat, as far as I know there is no easy way to connect any additional hardware (but to be honest I never tried...). If you just want to listen to as many as possible radio stations I'd like to recommend "Radio Droid 2" (you'll find it in the Google Play Store) and a stable internet connection. Hope that helps.
Bye for now Fred