if it's like the one on the picture, they fit just fine.
easiest way to get it in is to remove the battery and battery tray totally, then it'll just slip in easily.
the end with the tab on goes down behind the headlight, and the tab goes under the chassis rail then bolts up with the rubber bobbin supplied, then the other end of the pipe should sit pretty much bang in line with your MAF, joined up with the coupler supplied.
Pretty much everyone with a 1.8T has fitted one of these kits when they first owned the car.
Dubber: loud recirc is totally normal with these fitted, so long as it's a woosh and not a chatter/flutter