Had a cat back sytem fitted at Revolution Motorsport in Gateshead on Saturday. Initial impressions were "Woh, that's loud!" Not boomy, just loud, in fact on the drive home I was already contemplating having a resonated centre section put it. Happily after 200 miles it's quietening down nicely, not quite sure what's making it quieter but it is. At motorway speeds it's barely noticeable over standard but from pulling away from standstill and hard acceleration there is a nice roar. Milltek claim a 10% increase in power and the car certainly seems more willing to rev or is that just my wishful thinking... Best of all it pops and farts when you change down! 10 out of 10 to Revolution too, their workshop was like an operating theatre and they had the whole thing in and out in an hour.