Sounds to me like it is your flywheel. I thought I had motor mount issues and it turned out to be a seperating flywheel. The vibration from the flywheel feels like and looks like a motor mount issue when viewing the engine while reving. The B6S4 is known to experience this issue. Just talk to the guys at JHM and they can fill you in. I could be wrong, but I would put my money on it if the vibration seems excessive.