Re: 147 Roof Spoiler
Not sure about this holes in the window thing.
ePer lists different screens for the f/l and pre f/l but does not distinguish between models.
That being the case, the GTA roof spoiler ought to fit (about £200 from Stealers). My GTA's spoiler looks like it is stuck on with additional support from the window at the two ends. Rayq81's f/l has something similar but this has three supports over the glass.
Personally, I'd be very surprised if the rear screns were different, especially in order to have holes made before the glass is tempered.
Also on a personal note, I think the spoiler looks completely daft on a 147 - can't see it helping aerodynamically and it looks plain naff even on a GTA.