1. First open the iphone, find the setting interface of the mobile phone, and click the "Settings" button to enter the setting interface of the mobile phone.

2. Next, find the "Bluetooth" option in the setting interface, and click to enter, as shown in the figure.

3. Then turn on the Bluetooth function of the mobile phone, search the Bluetooth name of the in-vehicle system, and click Connect, as shown in the figure.

4. At this time, we open the setting options of the in-vehicle system, click on the Bluetooth inside, and make pairing connection. The pairing password will be displayed on the system interface, as shown in the figure.

5. When the Bluetooth of the mobile phone is paired with the Bluetooth of the vehicle system, you can click the music playing software on the mobile phone, as shown in the figure.

6. Select a song to play first, and then find a small button in the interface to switch between "cell phone speaker play" and "Bluetooth play". We can choose Bluetooth to play.

7. Also, if you can't hear the music, you can try to increase the volume of the car system, maybe you can hear it.