Brian, the filename is AUDIFW2003.zip
Download here,
http://www.lumpistefan.de/Audi/AUDIFW2003.zip
Then basically extract the zip file to a folder.
Then using Nero, Roxio or simillar create a standard data ISO CD (Not UDF format) and drag / drop the contents of the folder onto the CD.
Burn at a slow speed (I used 4x) and make sure the session is closed.
Restart the RNS-D holding down the flag and navigation buttons as you press power.
Select Eject CDRom, and remove the navigation CD.
Insert your FW disk, and at the bottom it should pop up next to CD version as 2003.
below that are two options, select the top one, not the TMC one.
System will check CD, restart, and update the headunit,
System will restart again, and update the graphics software,
System will restart again and tell you that the update was successful.
Remove now ejected firmware CD, and put your nav disk back in. Press the right knob in to accept, don't do what I did and press return as prompted.