PEUGEOT 308 Handbook page 316

04 MUSIC
Using the auxiliary input (AUX)
(cable not supplied)
Connect the portable device (MP3 player...) to the auxiliary JACK
socket using an audio cable.
314
Select Media to display the primary page.
Select change the source.
Select the AUXILIARY source. AUXILIARY AUXILIARY source.
First adjust the volume of your portable device (to a high level). Then
adjust the volume of your audio system.
Display and management of the controls are via the portable device.