I think Volkswagen definately missed a trick here with the Adv phone kit.
They should have made cars which have been specified with Adv phone kit to have its MDI installed under the armrest, that way you can use both music and adv phone kit functions at the sametime.
So as it currently stands, if I want to make use of the adv phone kit I wont be able to plug it into the MDI.
The MDI is located at the front under the A/C controls