My finished for now sub/amp install.
I picked up a GPS bracket so I just attached the PAC bass control knob to it. I could not bring myself to drill any holes in the dash. That location turns out to be very handy and at least I do not have to look at it.
The wires were very easy to run up to the dash without taking anything apart. Did Chevy do that on purpose? Kudos either way.
Putting the control knob in line after the LOC did take some of the kick out of the kicker. But then I adjusted the amp controls to compensate. The PAC control knob listed definite in and out RCA jacks, but no matter which I plugged in where did not make a difference.
The radio (non-HD) now has better bass than most of the songs in my ipod. Do I have to re-rip my 60 gig of music? And will my 60 gig become 120?
XM still sounds a little sad. I will let my free subscription run out.