There are 10 different locking lugs used by Mitsu (and I assume Dodge) all manufactured by McGuard (sp??). They code them by color, calling one shape black, one yellow, etc. The dealer has a master set. If you can figure out which one you need, you can call McGuard direct (search for them on this board, not sure of the spelling, there number has been listed before). You can get the lug through the dealer for about 15 bux, or about 10 going direct. The tough part will be figuring out which one you need, who knows, maybe you can talk the dealer out of their master set for an hour to bring to your house, since you obviously can't drive the car there with a flat...
Good Luck,
hal