Well .... Good or Bad, I finished installing my Alpine:
Yes, the stock stereo sits in the Trunk, powered by the relocation Harness.
So the Alpine is producing good sounds ... and the Stock stereo produces my dear Chimes ...
Couple of comments :
I also had to get the GM Antaenna adaper ... it cost me 14 bucks.
Then, I had a hard time fitting all the wires at the back of the Stereo ... especially because the relocation harness added a set of extra wires as well. On top of that, it took me a while to run this monster cable through the side panels, underneath my backseat ....
The I started to enjoy the Alpine and naturally I turned up the volume; now I heard some interference type "noise" coming from the front Left Speaker. It turned out that because the Stock stereo also is connected to the Front left speaker (for Chimes), it was somehow causing some interference, especially when the volume is high,
So I disconnected the Left Speakers from the Stock Stereo anyways for now ... I might get a little separate speaker later just for the Chimes. Oh well ...