The dreaded "base audio" upgrade...

[rpoitras]

If you're interested in getting a clean signal (no DSP, fully balanced) from the head unit to start with instead of the amplified signal w/ DSP you have now, you can add the HiFi option $676 to the vehicle options and default code the affected modules (CIC, PDC, etc.). This switches the outputs coming out of the HU and makes it a much better and clean signal to start with. No more having to "undo" the DSP added to the base system. This is the route I took and it worked perfectly.