just drove from chch to piction in my gc8, although im almost deaf from the sound of the exhaust... i notice there was a whistle like sound coming from the car\'s engine bay when i was driving it the whole way. i can only hear it when im driving between 90 to 100k in 5th gear. at first i thought it was the music, but then after listening to it for a while, im sure its the car thats making it. just wondering if any1 knows if it\'s the sound of the turbo or is it something else? the car drove all the way up with no problem at all, apart from the sound. also, since fitted the catless downpipe, when i lift off the throttle at 3000rpm, it makes the same sound as a butterfly bov.. except my bov is not a butterfly bov.. is that normal aswell?