can I use my mp3 player with my original radio?

I have a 2000 Malibu, with the original radio, and I'd like to hook up my MP3 player to it. It has a button labeled "AUX", but google searches I've done say that is for things like a CD changer in the trunk, stuff like that.

I know I could buy a replacement radio for it, and/or I could take the car to one of these car audio places, but I really don't want to spend that kind of money. I also know I could get something to hook up to the MP3 player that would broadcast over an unused FM frequency and play it that way. But I've been in other people's cars that did that, and it lost a lot of quality that way.

Does anyone know if there's a way for me to wire something up to the radio that would let me plug my MP3 into it, either with a USB cable, or even a plug like the plug on my ear buds? If so, how would I do it?

Thanks in advance for any help anyone can give.

Bill

There are write-ups out there for how to add an auxillary to the factory GM radios. I have seen them on other Grand Prix forums and have considered doing it myself.