I'm starting this thread as a reference source for those looking for OEM part numbers since they're not always easy to find...
FYI I'm using links to MitsubishiParts.net's online catalog to provide an online price check for various part numbers. I've found their price point to be competitive though of course I encourage you to check pricing with your local/preferred Mitsubishi dealership. Remember prices from MitsubishiParts do not include shipping/handling charges.
Please help out by adding part numbers that you've found useful to have and/or have had a hard time finding.
Also see the following EvoM thread: http://forums.evolutionm.net/showthread.php?t=124376