I'm trying to see if anyone had this this installation problem. I recently installed the px6 version of the tesla style radio in my 09 GS 450h. And everything worked fine until I raised the volume on it. My vehicle came with the Mark Levinson sound system and the sound was jacked up when I checked the balance, neither rear channels responded. And it sounded like everything was coming from the front channels. Is there a fix for this?? I could sure use some answers