Another thing i've picked up when looking more into this specific intake is this not so nice high pitched noise..
What makes the intake make such a horrible high pitched noise?
Another video of the same noise on a different GTI below too;
It's quite common, some sort of weird resonance.
I don't think it's the intake itself that causes it, rather that the intake amplifies or induces the resonance. Reason I say this is that for a couple of days during the summer mine was doing the same - but with a totally standard intake. Haven't heard it since.
Also, I'm pretty sure this just affects k03 cars, but don't quote me!