Hi mate, I was also debating whether to get a manifold but after seeing a few in action they seem a bit too loud for me, they are supposed to give a bit more power though. in the video I did have the cold air feed disconnected but I think about 70% of the sound was the exhaust. One thing that surprised me when I got the Milltek is that you can't really hear it inside the car, however outside the car it seems you can hear it more than the Viper
