Bluetooth pass through & other beginner quesions

As a heads up I haven’t installed the system yet so I’m not sure if it’s even an issue but. I intend to use this in my car as a head unit and interfacing with it wirelessly with minimalist IO (volume knob play/pause next track etc.)feeding a dsp and amps in tandem with an android auto dash unit is there a simple way to connect to the pi via Bluetooth and play music directly through it? And does the Spotify tidal etc. work without a Internet connection?
Or would it be better to ditch the android auto all together and build screen to work with the pi? Is there any gps / dash cam plugins I could grab lol