Rattling sound when revs drop

[Turbo Lag]

I've got a kind of rattling sound when the revs drop hard, coming from the engine bay mostly. You can slightly hear it in the video but it's a little louder in reality since my phone's mic isn't that good. I launched at the lights reasonably hard yesterday and the noise was quite loud too. I've found this old thread viewtopic.php?f=15&t=12326 here that kind of has the same symptoms too.

[Robbks]

Rattling heat shield

[Turbo Lag]

Heat shield would explain the noise while just revving it, but there's also a very loud screech/grinding noise (my dad heard it while driving the other Lib with the windows all up) when I launch hard in first (which can kind of be felt through the clutch pedal), especially on a hill where you need to up the revs for a quick start. The clutch feels fine but there's a squeak too at low speed, and I'm assuming it's on it's original clutch (at 152xxx kms), so it's safe to assume it still has the dual-mass setup. Mechanic took it for a drive and said he'd never heard this noise before from any car too. Could it be related?

[teK--]

Rattling heat shield

Correct.

Get under the car and tap exhaust from headers to rear mufflers using a screwdriver to see what rattles. Use (long) stainless steel wormdrive hose clamps around the heatshield then tighten to squeeze the halves together.

[teK--]

Heat shield would explain the noise while just revving it, but there's also a very loud screech/grinding noise (my dad heard it while driving the other Lib with the windows all up) when I launch hard in first (which can kind of be felt through the clutch pedal), especially on a hill where you need to up the revs for a quick start. The clutch feels fine but there's a squeak too at low speed, and I'm assuming it's on it's original clutch (at 152xxx kms), so it's safe to assume it still has the dual-mass setup. Mechanic took it for a drive and said he'd never heard this noise before from any car too. Could it be related?

The squeal when launching is probably the dual mass flywheel shitting itself. They are not designed for launching. Mine started doing it after the first track day and I never bothered to replace the flywheel am going to wait for the clutch to wear out then going to solid mass flywheel conversion.