Best setup for iphone?

[crashdesk]

Okay, so I have my GTI and loving it. I have noticed, under the arm rest a slot with a little diagram which I am assuming is for a slim ipod nano.

I have an iphone which I would love to connect to the standard radio, 6 CD changer unit and hopefully be able to control it with the MFSW.

What is the best setup as from what I have read some have limitations.

Many thanks,
C