I'd like to sythesize some of what I've read above in the sticky post to make sure I have it right. If I'm going to break down and put in a new head unit for wattage and so I have a cd player and mp3 input, this looks like what I'll need:

1. Wiring harness: I take it I will have to butt end connect the purchased harness wires to the aftermarket head unit wires, then simply plug the harness into the factory 16 pin harness that the oem radio unit just pops into.

The most basic I could get by with would be this one for $8:
http://cgi.ebay.com/2000-Pontiac-Bon...713.m153.l1262

I take it that with that harness II would lose my chimes, and also the radio would stay on when I turn the car off and get out of the car, until the ACC dies on its own 5 minutes later? I'm taking this to mean I could lock up my car and the radio would still play for 5 min. if I didnt power it off before I left the car?

Or, I take it that I could solve that issue with this harness for $80:
http://cgi.ebay.com/2000-Pontiac-Bon...713.m153.l1262


2. Antenna adapter: Use the VW one, which I don't have a link for but imagine it'* not too hard to find.

3. A 1.5 DIN aftermarekt unit looks like it would slide in, and I could take the factory clips off the OEM unit and attach them to the aftermarket unit, and pop the unit in with no additional mounting kit needed. (For a 1 DIN unit I'd need a mounting kit, but for 1.5 DIN it looks like I can go without.

So, does this sound about right?

Almost, as far as the radio staying on 5 mins after you get out, I dont think so. The wiring harness wont be able to power an aftermarket radio so you will have to run a power from either the rear fuse block or from an ignition wire. Then depending on what you do dictates how long your radio will stay on. I ran mine from an ignition wire and its stays on maybe 15 secs after I cut the car off. The downside is I have to have the key turned to ON for my radio to power on. Dont forget that you will need to cut the plastic out of the hole so your new radio will fit.

So what are you saying, with the cheap harnesss, the radio won't stay on after I turn the car off for more than 15 seconds?

Also, are you saying that wiring harness I linked to won't have the power wire to it already that I can put a connector to?

The cutting of the plastic doesn't sound like too big of deal for me.

No, if you run your power from the ignition like I did it will only stay on for 15 secs.

The wiring harness will have the power wire but the ribbon connector that GM used wont be able to power on your aftermarket radio. So you will have to run a power wire from either the rear fuse block or from the ignition.

It just seems illogical to me. The factory ribbon harness has power that will power a factory radio. But then that same power wire won't power an aftermarket radio if you hook the aftermarket radio power wire up to on the corresponding place on the harness? Can anyone verify this? Thanks.

I did ask a guy at an audio installation place and he said with that special integration harness, no additional power wire running is necessary. I'm asking above about the cheap $8 one. But I find 01 bonne is right. Confirmed here:

http://www.bonnevilleclub.com/forum/...tennae+adapter