Just bought my first BMW, a 523 E39. What a great car. I’m trying to sort a few niggles and hoping someone on the forum can help. There’s an Alpine CD auto-changer in the boot but pressing the mode button on the player only toggles between the radio and the cassette and it doesn’t recognise the existence of the CD player. The CD player is connected to the BMW electrics provided for the purpose via an interface that presumably the Alpine unit needs to match its wiring to the BMW wiring. Any suggestions how I get it to work?