The exhaust should fit an N52 as intended with no issues. Check the emissions sticker under your hood. If it says SULEV then you have an N51. ULEV is N52.
I assumed I had an n52 till I checked. If you haven't looked, you really should. I was a bit surprised.
On N51's the pipe after the resonator is a larger diameter than the N52 cars and I needed to have it welded on. For N51 cars, a couple inches will need to be cut off of the AA exhaust so that it'll weld up properly.
I have some pictures on a review thread I posted a few months back if you're curious.