Connectivity issue with a2dp_source and bluetooth car audio system

[aponomarenko]

I tested ESP32-WROOM DevKit v1 with a2dp_source example for audio stream to the JBL Bluetooth speaker. Connect and transmit audio without any problems. But I can’t connect to a Bluetooth car audio system Volkswagen. Log file showed that in the discovering mode the car audio system transmits mac address with 2 properties - COD and RSSI but the third property BDNAME is transferred separately. Why does the car audio system can't detect the esp32 module when it works as source? If the DevKit works as a2dp_sink example, then the car audio system detects it but can't get connect with it. Why does the car audio system work in different way? What is the problem?