Integration of Audio 30 with phone in ML430

Hi, I have a european ML 430, with an Audio
30 head unit - I want to integrate a mobile
phone with it, so phone gets used via the
Audio 30 keypad.
Other models (such as CLK) have a factory
fit option for this, but not ML for some
reason. Factory fit allows a Nokia 3110 or
a Motorolo phone
I know it integrates using the optical
interface for the CD player (D2B)

What do I need, (lets say to integrate
the Nokia 3110 (european) handset) ?

European dealers seem scared of the Audio
system - their normal response is that its
far too complicated :-)

The ML is 2 months old, and is the new
European build with the better interior -
it seems to be prewired for something which
uses extra co-ax, ie either phone or sat-nav