Ipod/mp3 to standard gamma H/U mk4?

[AJ_EQ]

So basically would this work, plug in the back of standard H/U. then get the opposite cables to 3.5 jack or ipod connection?
http://cgi.ebay.co.uk/VW-SHARAN-GOLF-AUX-RCA-MP3-IPOD-LEAD-CT29VW01-/290468719168?pt=UK_Cars_Parts_Vehicles_Terminals_Cabling_ET&hash=item43a148ea40

This is the cheapest option Ive come accross.  Would I be right in thinking it should play incoming calls through the stereo as well, if I plugged in Iphone, same as a aux on the front right?

Also wondering what the audio quality would be like, im guessing cd standard...