Bunch of comments on this. First the wiring harness for the aftermarket radio isn't cheap anymore to get the door chimes to work. Best Buy quoted me $120 and I got mine off e-bay for 80 after shipping. The steering wheel controls were another 40 (best buy didn't have this included either).

For the Tire Monitor, there is a manual way - once the tire is filled to proper levels, start the car, pull your headlight switch half out, then turn the dome lights on and off 3 times by turning the **** all the way right the back left. This is on page 5-74 of the 2004 Monte Carlo Owners Manual.

You can check it online here. Just goto page 5-74 and it is in the bottom left corner.

http://mymonte.com/tech/manuals/2k04montecarlo.pdf

 

i have a 2002 ss. i decided to leave my factory radio in for the sake of having the steering wheels controls and onstar. you just need a modulator which costs about $22 at best buy. then maybe an eq component for the sake of adjusting my subs without changing settings on my smaller speakers. i was gonna get another Sony Xplode cd player for the sake of havin an adjustable sub control (which is a great thing to have), but i opted to keep the factory because i don't wanna pay for the extra modules.