I suggest you contact your local dealership's service department. They will be familiar with the specifics of each vehicle and may be able to tell you if the mounting holes are the same or if a modification is needed.
I have a GT stock spoiler I will damn near give you. If your interested. Its sitting at my dads work collecting dust. Torch Red, took at off at 2,000 miles.
I can say that the mounting holes are the same now that the spoiler is mounted. I should mention rhat the V-6 spoiler is mounted with not only the 4 studs and nuts, also used is about 4' of 1 1/2" double back tape. Not easy to remove the old spoiler without damaging the paint, but it can be done with some patience.