Things to try.. if you havent already.

While turning on and off ignition, press eject button as well as each individual CD buttons. Since everything is stuck you got nothing to lose -- a few of us have had luck hitting the left side of the changer while pressing buttons and turning ignition off and on.

And I dont know if this could help but some owners have said they had luck disconnecting and reconnecting the battery.

The one time I had a stuck CD several years ago, I worked on it for at least 30 minutes before it coughed up the CD. Good luck