trailblazer audio system specifications
How to play MP3 CDs in trailblazer LS 2007 Audio system?
Did it come with the capability to play MP3's? Not every car has that feature yet. Check the owners manual, if you can play mp3's it will tell you how. If it can't, there are radio attachments that you can attach to mobile mp3 units, like ipods, to make them play through your radio.
Blue book for 2003 thraiblazer 2 wheel drive and tow package