Subject: need OEM parts
Question:

Hello-

I need one replacement lug nut for 1999 Mit. Eclipse Turbo 2wd.

-what is the part number and where can I find this part??

Answer: Don,
The part number is MB579290. You can go to any Mitsusbishi dealership and get one from the parts department. They are about $2 a piece. You could even call up a local salvage yard, and ask them if they have any lug nuts to match that car. Any Eclipse with alloy/aluminum wheel made between 1991-2002 use the same wheel nuts.
Good luck!