I recently replaced my speakers and installed a "Cleansweep" and amps. This is on a B7 S4 that has Bose and Nav from factory. After the "upgrade" I get a bad hissing sound and one of the speakers chitters. The shop claims that this is because of the way that Bose stuff is designed. So, 2 questions:

1. is there a way around the Bose issues?
2. if I end up replacing the entire head unit, is there one that has Nav, XM, will work with the stock CD changer, and will work with the stock steering wheel controls?