2GNT | caps
Mitsubishi's Computer Automated Parts Search, the program dealerships use to find parts for your Eclipse, is now in the process of being webified by Team 2GNT.
You can check it out here: http://www.2gnt.com/CAPS
Note that at this moment in time, you cannot navigate down to the level of Mitsubishi part numbers, only to the PNC level. However, PNC's are used to generally describe a part minus information about model year and trim (part numbers can be different between year models, PNC's are always the same) so i imagine you could go to a dealer parts counter with your list of PNCs, tell them your year and trim, and they could very quickly get you exactly what you need out of CAPS.
Someday, it may be possible to turn this into a web enabled app capable of storing the entire database of part numbers matched to PNCs matched to drawsings, but right now that is beyond the scope of keeping me busy while not working at the office ;-)