cavalier z24 wiring

I have a 2004 Chevy Cavalier Z24 and i was if i need a special wiring harness to install my new deck, my car has a factory theft system (Passlock) in it and has a red flashing light on the fastory MP3 player.  And also wondering if anyone has a wiring harness for a 2004 Chevy Cavalier Z24

Any Gm vehicle newer then 99' comes with what they call " claas 2 " circuitry. There's an urban myth floating around that if you disconect the radio and hard wire it you're airbags will go off and ya lose all your functions. Not true. I had a 01' and did it. All I lost was the annoying buzzers and my interior light.

The best way to do it would be to go out and get the adapter. It's like 90 bucks.  You can also go out and get the factory radio relocation harness for about $50, which is essentially a splitter that hides your old radio behind the dash and allows you to run a new one off the same closed circuit.