Have just bought an adaptor that allows you to connect any mp3/ minidisc/CD player to the standard Renault head unit. It plugs into the autochanger socket in the back of the stereo. And connects to the headphone jack on the player. Not fitted it yet but hoping it will be good. Cost £55 sounds expensive, but much cheaper than buying a new ipod compatible unit. Check out http://www.connects2.comwww.connects2.com it is an AUX in adaptor.
This cannot be used in addition to a multichanger - it replaces it.
Andy