My 91 Formula didn't have a wing on it when I bought it but I found a wing from a 91 GTA and have done some test fitting - I'm still in need of a gasket/spacer between the decklid and the spoiler itself. I've heard butyl tape, but my local parts store (Advance Auto) didn't have anything. What have others of you used? Where can I get it?

 

Even though I have a different style spoiler than yours I found what worked best for me was small rubber washers. I just placed one 1/4in thick washer on each of the eight bolts that went into the deck and tighten each down mashing each washer just enough and allowing the spoiler to almost touch the deck .They also act as a sealer keeping water out of the holes and the deck itself. It only takes a few minutes to do so if your not happy with it your only out a couple bucks at most. Mine did not leave any large gaps so it was not necessary to fill all the way along the length of the spoiler and that worked fine for me. (be sure the washers are thick enough to get some compression.)

 

ever think of just getting some thin rubber matt and cutting ur own gaskets? would probably be cheaper then getting ones pre cut and only take a few min to do.. altho thats not a bad idea with the washers either.. simple and effective