hello! we drive an audio a6 ez 2001, and would upgrade this “sound” a little bit. currently an audio chorus + original front system is installed. (the devil knows how to install such a system in a 45 teuro vehicle!!!) would like to upgrade to an original concert radio because of the matching optics, and then take the front speakers to the rear, and operate a reasonable front system over a small end stage. yes, that goes at all, with what cost I have to use and can you already listen to music? direction of music: everything! thanks already, torsten