Would like to buy a used stock skid plate (under cover). Part #12 in the diagram contained in the link. I have the other two, #13 and #14.
2004 Toyota 4Runner Parts - Conicelli Parts Center
I bought one used the seller said was off of a 2004 but the bolt holes didn't match up. Apparently the 2WD and 4WD are different. I don't know which it came from. Either that was the reason it didn't fit or perhaps it was from a newer 4th gen.