David, Hmm, I can't see how the cd plug would cause this but I suppose it's possible.

The BC button should work regardless of radio/nav type.

I have retrofit nav in mine and other than the speed sensor not being connected properly (pin 8, now working), everything works, funnily I used the BC button last night on the way home.

Do you have a diagnostic tester (DIS/GT1 or carsoft etc).

If you were close to me I'd say pop round mate.

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Sept 03, M3, Silver Grey. Retro-fits: Modded Mk4 DVD Drive, OEM Bluetooth, VR Control, Rainbow Speaker Upgrade, Sony SOT Amp, HK Sub, CCFL, Intravee II, NightMode.