Unused wiring plug behind card reader

[Malroy]

Hi all, My son borrowed my Meg 2004 CC the other day, was a bit brutal inserting the key card pushed the card reader unit out. Removing the centre paned to reinstate it I noticed there was a unconnected plug attached to the card reader loom with it seemed no place to connect it. All the functions on the Meg work so does anyone know what the unused loom connection might be for. Perhaps keyless entry that my Meg doesn't have? Thanks

[shakennstirred]

Maybe for the CD changer that you can get, it sits under the radio.