I have a Xantia with the genuine 4035RDS radio with steering control and the Clarion 6 CD changer.
I would like to change the CD player with a 10 or 12 changer that is compatible with the rest of the unit.
I found this link and asked them for more information, but they never replyed.
http://www.yourcarparts.co.uk/trolleyed/73/index.htm