code

there are various people that offer decoding and if you radio is a Becker (BMW professional) or Philips (BMW Business) or Blaupunkt there are some free decoders if you search the net. You will have to enter the radio's serial number, which will require you to remove the radio to read it.

But with the serial number, assuming its a BMW radio, even BMW dealers can get you the code (for a small fee).