If you have Nav you'll have to go with the Dension. Even Porsche dealers sell it as its the only viable options. However viable is less than perfect. Mine (after being updated and replaced several times) will also plays but you never know what it's going to play. The ablity to navigate the Ipod features seems to work after it's had a very long time to sync up (sometime over a half hour). The thing isn't cheap either. It cost the same as a good double din head unit with better nav and ipod interface. Of course to do it right you have to dump all the Bose amps and speakers. So you looking at about $5K is you don't go nuts.