Replacing stock stereo, I was told I need an electric adapter
 

Ok my stock radio in my cobalt is out, and I was told by a local music install shop that I needed an adapter of some sort because the low fuel chimie, door chime etc, is run through the stereo speakers. So If I go with an aftermarket radio, what type if any adapter do I need? I plan on going through best buy to get my stereo, their install prices seem reasonable. Any thoughts?

Yea its a door chime module. otherwise you will not be able to hear your blinker, door chime, low fuel, lights on warning, any warning chime for that matter, nothing. Also, it gives you one of the power wires you need (either the constant or the acc... I cant remember which one). But yes that is correct.. you need that piece. Its about $100 - $200 depending on where you go iirc

metra gmos lan 03 or 04 (pioneer)