Early production 2004 models had a dual mass. The later production model have a solid flywheel. If a dual mass fails the part # is succeeded with a solid flywheel and bolts. I sold one today along with the clutch assembly.
Dual mass flywheel 3C3Z-6477-AA is replaced by:
3C3Z-6375-BA, 3C3Z-6379-CA along with the newer style clutch.