Managed to reattach the heat shield, as originally thought this was the cause of the blowing sound coming from the rear of the car, (exhaust) But after going out in the car, its still sounding bolloxed, getting really annoyed with it now, I've checked the Cat and there's no rattle, can't feel any gas escaping along the exhaust line. I specifically bought the right middle exhaust and back box for my car but I'm now beginning to think I've been ripped off and have actually got the wrong exhaust.

would a 1.6 exhaust system sound like it's blowing on a 1.8 model car?