I did a search but with conflicting knowledge on every thread / website I am unsure what is required for the head unit I want to buy.

I have a 2006 Cobalt LT, no pioneer, no onstar, none of those goodies. Just getting this simple pioneer:
http://www.bestbuy.com/site/olspage....=1218056226796


So far I believe these are the items I need...

Harness:
http://www.crutchfield.com/p_1207021...s.html?tp=2977
Antenna Adapter:
http://www.crutchfield.com/p_12040GM...a-Adapter.html
Dash Kit:
http://www.amazon.com/Metra-99-3302-.../dp/B0007WTF9S

Then all I have to do is connect all the wires on the harness to the aftermarket radio.
Place the radio in the dash kit, connect the antenna adapter, connect factory harness to aftermarket harness, and slide it all in?

This will leave full DIC functionality?
What is required to keep the radio on until the door is opened but key is out?

 

I have the pioneer audio but no onstar. Installing using a regular harness will disable your door chimes and also may trigger a check engine light.
This is the piece you need
http://www.crutchfield.com/p_127C2RG...gm+integration

also, when i ordered my h/u from them they gave me 50% off the adapter. Also a free antenna adapter and dash install kit.
My steering wheel controls don't work but its the only issue i have.

 

he has an 06 no worries on the chimes. onstar is a bitch to retain thou

everything u have is correct but you will need to run the red acc wire to the fuse box. tapping the sunroof fuse tends to retain the RAP feature ur looking for (stereo still on until the door is opened) but its really 75/25 so it might not