Simple bare-bones ESP32 A2DP sink for Subaru Outback. Tested with a weather-band capable unit that has a built-in CD and cassette.
Unlike other solutions, only requires one pin - although this technically violates the max input voltage on the pin. Seems to work...
Uses the next/previous CD buttons to switch tracks.
Uses https://github.com/pschatzmann/ESP32-A2DP and https://github.com/xc-racer99/MBus-Subaru as Arduino libraries
Inspiration taken from https://github.com/kjanesch/pseudochanger/tree/master/pseudochanger with the info from https://forums.nasioc.com/forums/showthread.php?t=2536066