On an 81 Z28 rear spoiler, center section on the deck lid. There are 4 studs in the middle of the spoiler that mount to the deck lid. Then there are 2 holes at each end of the spoiler. My question is, what goes in those holes?? I don't see any threads in the holes. Are studs supposed to go in these holes? If studs go into these holes, do the threads just bite into the plastic spoiler? If studs really go into these holes, can someone give me a clue as to the size?? I've looked in several catalogs for spoiler mounting hardware, but I don't see any mention of studs or bolts. Thanks in advance for any and all feedback.