2004 Impala CD Stereo Question

I would like to keep the stock premium system for at least a little while or until I get a different car. What does the Aux port do? Is it available to use with something else? If I could plug my iPod / iPhone into my car stereo, I would be perfectly fine and very pleased. Is there a way to interface a simple audio cable (headphone cable) directly into the car stereo? Are there two RCA plugs on the back of the unit? How would XM interface because it works with XM..?

I don't want to deal with FM transmitters and don't even have a cassette port. I have the iPhone and with a proper mount so it can charge in place, I really don't need any info on the stereo itself because the iPhone alone is amazing in its abilities to display things on its large screen--and I could play video because nothing would inhibit that!

I wish, I saw that too. apparently the aux is for nothing. From crutchfield you can buy a device that fakes out your radio into thinking you have the GM cd changer. This device allows you to plug in an portable music device like an ipod or palm pilot. Right now I use this little device I plug my palm pilot into, then insert into the cig lighter for power. On the top there is a small lighted dial with the fm band. I find a place on the car radio fm band with no broadcast, then i tune the device to that and the device broadcasts to the car radio. It has some static, some volume loss, still is better then nothing. I got mine at newegg.com simular one i have seen at wall mart

Excellent News!

I actually found a solution but didn't think posting here would matter since it didn't appear that anyone was reading it. I wrote up a HUGE ~10,000 character summary of my complete project. It turned on AMAZINGLY well! I now am able to play my iPod--I use my iPhone! through my in car, stock stereo with CD player (no CD or changer or XM).

Read it here. Tell me what you think. I'm VERY happy. Total price was around $120 and I installed it myself.

http://yabb.jriver.com/interact/index.php?topic=41707.0

BTW: the device I purchased interfaces directly with a lot of recent GM vehicles.