[chittychittybangbang]

It's a "normal anomaly" with your car. Common problem and it most likely has nothing to with the flywheel. Aftermarket tuners claimed to have fixed it but aren't saying exactly how. From what I understand it's believed to be mostly from EGR tuning. This could change as knowledge about the car matures and more info comes out. You should be able to minimize it by changing throttle position.