If that's dead then a used CD unit will need component protection removed to work in your car. How desperate are you to have CDs? I ask because you can swap this for the AMI unit (ipod, USB MP3's etc..) which has no CP. Essentially a 10 minute job just by dropping the glove box and switching units and using the same connections.
Here's a used AMI, if a little overpriced... I have part number 4E0035785C AMI in my A8
http://www.ebay.com/itm/152345285646?
honestly I woud rather have the ipod usb and mp3 capability so maybe I would be wise to get on ebay and at least take a look, but again based off of my optical bus scan is that whats wrong with my system exactly? im new to all of this lol