Moin, it’s me again to buy hsbe before the multimedia radio from Erisin, now the question is whether I still need the extension cable from the rear to the front to the radio. Vehicle is 330 convertible 04er with Navi Prof. Here is the radio and extension cable:http://m.ebay.com/itm/131047433514?_mwBanner=1http://pages.ebay.com/…/?…