1999 S3 (APY 210).
Strange one for you. So I was out today having a drive, enjoying the weather, the views etc. Got on my local dual carriageway and accelerated in 6th from 3000rpm, when I did so the turbo didn't "sound" how it should do, instead of a shhhhhhhhhhh (like they all do, it was more of a shhh shhh shh shhhh shhhh shhhh, for 1/2 - 1 second then normal sounding boost. This wasn't full throttle acceleration btw, something like 1/2 throttle or so.
Now this only happens when I have a passenger in the car, normally a lady who's a size 10, so no fatty, but when i'm alone it sounds normal.
Vagcom comes up all clear, does this sound like a boost leak or something much more sinister?