For the rest of the exhaust, is it Corsa cat-back or nothing? Since you decided to spend your allocated funds on headers and tune, which I would've done, you could have the whole package for just a couple hundred more (less if you weld it in yourself) if you went with a more affordable muffler. Unless the Corsa cat-back is a different size of pipe or if you want that brand for bragging rights, I don't see any benefit in replacing the stock piping and there are plenty of cheaper muffler options that give a quiet but noticeable sound with no drone. You could get one of the Magnaflows that are always mentioned here and whatever dual exit tip you want and have it welded to the stock piping. The Magnaflow 12589 is the most comparable to the stock sound. There are copies made by AP Exhaust that are virtually identical but without the Magnaflow logo stamped in the case for about half the cost. I got AP's copy of the Magnaflow 12259, which is one step more aggressive than the Magnaflow 12589 (18"L by 8"W body versus 22"L by 11"W body) on sale on Amazon for $31. No drone when cruising and has a deep but mellow tone when accelerating. Next to a retaining wall or under an overpass with the passenger side windows down, it sounds pretty wild at WOT. I think it's the best of both worlds and at a bargain price. I understand that there are good and not-so-good qualities of exhaust system materials and builds. But, it's just hot gasses- it doesn't care what name is stamped on the pipe it's going through. The stock exhaust is perfectly adequate in size and quality for you at this level and a packed fiberglass muffler is pretty hard to screw up, popular brand name or not.