Over on the MK6 GTI forums it has been discovered that 2011+ GTI's have what's called a Soundaktor that pipes simulated engine noise into the cabin.
<---- that was my reaction
On the GTI the controller is under the rain tray right next to the ECM and only takes about 2 minutes to unplug. The "speaker" is mounted to the center windshield support along the firewall and harder to get to. It basically sends vibrations into the firewall and windshield to create simulated engine noise in the cabin.
Full details in this 25 page (and growing) thread: http://www.golfmk6.com/forums/showthread.php?t=33595
I have disconnected mine and the sound difference is striking. The car is much quieter and all of the deeper resonating bass is just gone. The thing is, this is also on the TT as well, probably starting in 2011, but who knows. At least the 2011's and newer definitely have fake engine noise in the cabin. The actual part numbers are Audi parts, and all the documentation points to this being in use in the Jetta GLI, Beetle Turbo, GTI, Golf R, S3, and TT.
I'm posting in here because my boss has a 2011 Audi TT 2.0T, and after riding in my newly quiet GTI today, he's wondering if I can disconnect his Sounaktor. I would, but I'm not sure if it's in the same place on the TT, and I'd rather not start ripping into my boss's rain tray if it's not in there. Page 20 of the above thread shows how to get to it on the GTI.
Anybody have any idea? I'd love to help out my boss.