7 days of ownership on my 2006 S40 T5, buzzing noise on payment and certain radio sounds were driving me nuts. And it sounded like the waterfall was making creaking noise.

I unscrewed the T10 screws in the back of the waterfall.

Got 3m/scotch Velcro, used the felt side. Cut a half inch by 3/8th piece, drilled hole felt side up.

Then took screw and screwed it through felt side down.

Screwed back into waterfall, torqued appropriately. Sound and buzzing gone.

Then I took my interior prop/install tool (plastic pieces), and pull the waterfall enough up, to wedge some felt side Velcro in between the plastic side of the waterfall and where it meets.

Very quiet now.