Anyone have anything on a VW UP engine rattle at 2500rpm?

Iím guessing itís a resonance frequency causing a rattle in a piece of engine bay heat shield tin.

But has anyone come up with a fix, eg adding grommets or some sort of off the shelf engine sound proofing membrane/ fabric?

Iím also guessing it is from something near the gear box as it wonít make the rattle if in neutral and revíd through 2500 rpm but it will rattle if in gear at 2500 rpm.

Cheers
James