MP3 Changer
MP3 Changer 
Joined: Nov 2003
Posts: 11,334
Likes: 347
From: Jacksonville, FL (originally from Toronto Canada)
There is a changer called the NEO Changer that comes with adapters to connect to just about any factory radio (including the Monsoon). It plays MP3s and regular CDs and just plugs in to the original changer harness with an adapter cable. The problem is that they don't have a very good reputation for reliability. "Piece of crap" (or words to that effect) is the most common comment I've heard.
If you can find a changer that will output to 2 RCA cables, then you would be able to hook that up with a GM AUX-9 adapter and have the sound feed through there (existing CD Changer wiring). I don't know any changer off the top of my head that outputs RCA cables.
The "Neochanger" is the only unit that supposedly can retain regular factory functionality through the factory head unit. In reality, they really are crap. Don't think people are being too picky and you'll be lucky - they are crap crap crap. A total waste of time and money and you will regret it. If you don't believe me just TRY and find any information about them on the net. You don't want to buy a product that google doesn't know.
You would be 1,000x better off getting an aftermarket mp3 changer and running it through a GM AUX adapter like FBDYLVR suggested, you'll just have to deal with mounting the remote somewhere.
In the end I recommend using the GMAUX adapter with an ipod or similar MP3 player. The overall cost and sound quality is similar, and it is easier to transfer files then to make a bunch of MP3 discs. Plus you pick up an MP3 player to use.
Keep in mind it'd be much cheaper and sound much better to use an aftermarket MP3 capable deck. I understand some people want to keep a stock look, but you are spending more money for lesser sound quality by chaining yourself to that head unit.
You would be 1,000x better off getting an aftermarket mp3 changer and running it through a GM AUX adapter like FBDYLVR suggested, you'll just have to deal with mounting the remote somewhere.
In the end I recommend using the GMAUX adapter with an ipod or similar MP3 player. The overall cost and sound quality is similar, and it is easier to transfer files then to make a bunch of MP3 discs. Plus you pick up an MP3 player to use.
Keep in mind it'd be much cheaper and sound much better to use an aftermarket MP3 capable deck. I understand some people want to keep a stock look, but you are spending more money for lesser sound quality by chaining yourself to that head unit.
