Hello everyone in my XC90 have the high-performec system with separate subwoofer. At the time of the consultation my friend explained to me that the premium is not lone, since there is almost no CD which are recorded for this mode. After I recently made a test drive with a V70R, I fell out of all clouds. The sound experience with premium is significantly better. Can I now upgrade the premium? Thanks for your help Stephan PS sometimes have the feeling that the sub even If you turn it off, only small differences are audible. Can you trim it in a submenu?