I got an 89 GTA and I was wondering if the spoiler for a Firebird with fit on it. That flat wing spoiler not the wrap around one currently on my GTA. Reason I ask is because I want to get the louvers and it seems the GTA spoiler will not work with it.

I've seen louvers used with the wrap around spoilers, I think you'd be fine. The flat spoiler will fit your car but you will have to drill new holes and fill in the old holes.

If you are planning on getting the current after-market louvers that are out there, they definitely do make some for the wraparound style spoiler. I would, however, advise against changing your spoiler simply because you want louvers. Either get the right style needed or not at all. It will cause many more headaches than it would be worth. As somebody who was lucky enough to find a pair of OE louvers, I would not have put them on my car if I couldn't get a set that actually fit.