Hey. Yeah I finally worked out what was up with mine. Bend down and look under the front bumper - do you see a load of oil and grease coming from the engine cover? Well it was pissing out of mine. Turns out the hose had almost come completely off the wheel side of the intercooler as the retaining clip had snapped in two. Proper **** design really but there you go. Just needed a new clip from the dealer, though I got the hose as well for good measure as the lugs had worn. Make sure you get the right one though as there are loads that look the same and the guy at my dealer was pretty useless! Bitch to fit but I managed it with just the use of a pit. Now I still get an anoying whistle but as far as I know that is unavoidable as the turbo loop on these engines are notoriously leaky, but I'm not losing a significant amount of pressure so I'm happy.
So yeah, get yourself under your car, take the big cover off and be prepared to get very dirty!