Well of course there is that annoying chime reminding you your keys are in the ignition.

So all you have to do is remove a single plug, and the chime goes away.

This mod is totally reversible, and doesn't disable the lights-left-on chime

This guide follows the "easy way" post in the how-to located here:

http://www.msprotege.com/forum/showthread.php?t=43417

The only tool I needed was a Philips screwdriver.

First raise the steering wheel to its highest point. 

Locate and remove the three screws holding the casing together.

Pull the release lever out of the way. Then pull the casing apart by pulling down on the back of the casing.

Once open locate the key-assembly, and the small two pin connector vertically plugged into the assembly.

It has a blue wire and white wire.

Pull this connector out.

The second I pulled this out my chime stopped. 

Put the casing back together.

And the screws back in their places.

(Black screw is towards front of car)

Done, feel free to blast your music with your doors open.

Update:

After finding out that removing the connector also disables the courtesy lights when you exit the car, I decided to go back and do it the harder way, which didn't take more then an extra five minutes.