Hi, I've got a 2003 B6 S4 and I've just had a new sub frame fitted, the old one was dangerously rusted. A mechanic friend did the work and when he was away when I picked the car up. Upon driving it back, I immediately noticed a couple of new noises. Firstly and most noticeable while driving a is a sort of windy whine that increases with the revs. Most noticeable between about 800 - 2000rpm, after that the engine and exhaust starts to drown it out. It's a bit whiny and possibly a heavy rush of air, although it's a bit hard to describe. Kind of a cross between a supercharger and a jet engine! On top of this the car feel like it's idling a tiny but faster than before, plus when I dip the clutch to change gear, the revs hold for a split second before dropping, possibly even increase a fraction before dropping. This is all new. Second thing is I've noticed a slight 'squeal' as I approach full lock when manoeuvring at very low speeds. I'm guessing the second is something to do with the power steering? Any thoughts on the first issue or where to start investigating?