Could be drivetrain, engine mounts, or even an exhaust bracket too? I would recommend having your service center facilty take a road test w/ you so they can possibly pin point you into the correct direction.
I tried to move up my appt at Tuffy, and they said they couldn't do it and weren't even sure if they would get to my car on that day (they estimated it to take 90 minutes. I went to Merlin, and they replaced the flange (they had to cut and weld). They did the work right away for $50 less than Tuffy and it took less than 1/2 hour. Car is no longer making any noise and the repair came with a 2yr/24,000 mile garantee. I'm happy with Merlin. Not happy with Tuffy.