Thanks to Bob we now have a how-to on doing the door dinger mod for 2004 (and I assume this will also work on 2005-2006 but I cant be sure)
As Bob said above, its is exactly the same as 2003 and down only in a different location...
You will need to remove the right side kick panel to expose the wires needed to do this mod. This is a fairly easy mod to do and I think the hardest thing was to remove the plastic screw holding in the kick panel without breaking it. By doing this mod you accomplish removing the door dinger when you leave your keys in the ignition and you also disable the headlights on chime.
In this first pic you can see the 2 connectors (circled) where you will find the two wires needed to do this mod. There are 2 bigger connectors and 1 smaller connector. The YE/BLK wire you need to find is in the bigger connector in the middle of the 3 and the GREY/RED is located in the smaller connector to the right of the 2 bigger ones.
In this 2nd pic you can see the cut YE/BLK wire and you can see where it is tapped into the GREY/RED wire on the smaller connector. You should tape off the end of the YE/BLK wire so you dont have any electrical problems.
Thats it. Put everything back together and you are done.