I know there have been some topics concerning this, but I have finally got the Z1 in my 1998 C5 after buying a custom dash, but now my bose system is acting. The sound quality is horrible. Does anyone know how to fix this? I have read that the impedence levels of the bose system arent paired with standard after market ones, but how do I fix this? I dont want to replace the sound system, because i just spent 18k on this car, and 2-3k for some pioneer navigation and accessories.

How did you interface the avic with the stock bose system? A part number for the harness you used would be helpful. When you say acting up what exactly is the problem. In the end I leave you with my favorite quote No highs, no lows, it must be bose.