My A3 currently only plays through one speaker. I was told by a garage that it showed as the amplifier, yet I was told by Audi that my system has only the basic Audi Chorus, and does not have a separate amplifier. I took it back to the garage and told him and after inspection he then told me to replace the stereo unit itself. Any suggestions or further thoughts please? Also if by replacing it it solves the problem can I replace it with an Audi Concert instead of Chorus?