what's the deal with putting an after market stereo in an 04 sunfire. apparently you need and expensive wiring kit so all your stuff works like the air bags.

What you need will be the adaptor plate to install your high bucks stereo for your model of car. This comes in a kit if you buy from a aftermarket auto stereo business. The only wiring harness you will need if you plan to add amps, and to all the speakers.

With 2000 and up GM Vehicles, most wiring does run through the head unit of the stereo system. For a 2004 Sunfire, the main concern you will have is the Door Chimes. When I purchased my Clarion head unit from crutchfield.com, they told me which harnesses, etc. I would need. The chime module has saved me on a couple of occasions where I would have left my lights on or keys in the car. If you do not choose to do this, You should retain all stereo and airbag functions with a standard wiring harness, but will not have the "idiot chime" function as it is called, because factory setup runs the chime through the head unit to the speaker. Hope this helps!