Looking at your spoiler, it looks like the CAE ones that I have seen - i.e. flat!

My spoiler was supplied by Craig, but I dont remember if it was to fit the Corse, the Hawk or if it was a lister bell item.

Click image for larger version. 

Name:	Roof Spoiler fit.jpg 
Views:	375 
Size:	57.1 KB 
ID:	3406

The main thing is that it has the curve, when i fitted it, I had to use a small amount of filler to get the spoiler to fit to the body perfectly, but that is common for allthe kits (apart from the Lister bell of course!

I would guess that the same spoiler would fit your car..