Heater Assembly under dash rattling...help! Fabia VRS 54 Plate

Hi All

I've owned the Furby for 7 weeks now and I have tried several times to pack the heater box assembly but it still rattles when I start to drive off (around 1000RPM) or when in third at low speed trying to accelerate. I have packed every possible nook and cranny with foam but no joy. It seems the heater box walls are vibrating and causing the rattling sound because it stops when I put my hand on it and apply a bit of pressure.

I have done the 'cork' method behind the center air vents but this did not have any effect.

Any advise greatly appreciated.

Cheers

Marc