[AllHailKingVolvo]

I got to it this afternoon...I found a microfibre demister sponge (once the microfibre outer was removed) slotted in perfectly when cut to let the stick slip in, and I peeled back the carpet and lined the transmission tunnel around the stick porthole with sticky backed silver soundproofing sheeting.

I then refitted the gaiter and secured the outer lip to the tunnel with a strip of soundproofing sheet on each side just for good measure, and refitted the carpet.

The difference is immense...the car is SO much quieter!! Absolutely blown away by the difference. So much so I'm now pondering soundproofing the bulkhead and bonnet...

Thanks again for all your help and advice!