I finally figured it out.


I didnt even have to unplug the nav. all you have to do is hold down the eject button and wait while you hear the cd trying to read (I think I heard it do this about 4 times) keep your finger on the eject button the whole time and once you hear the nav unit stop trying to read the disk (about 1.5 - 2 min) let go of the eject button and press it again quickly and the disk pops out for you to throw across the room.
I even tried it twice to see if I wasn't just getting lucky. It came out both times using the above method.

I have an MKIII 2001 M5