I just recently went through this experience and I have useful information for those wishing to hook up this ****ty system. I changed all of the speakers out using Boston Acoustics. I also had a 10" sub box firing rearward built for some subtle low end. An Alpine 5 channel V12 is running the system. I left in the Symphony, HOWEVER, if you do this you will need to visit www.soundgate.com to purchase the line out converter to make an aftermarket amp work. Otherwise, you will have crackling, distortion, and crazy engine noise. They make a great product. Good Luck!<ul><li><a href="http://www.soundgate.com">Great Converters for the A4 Symphony</a></li></ul>