"Interior Filter replaced, now a metalic vibration"

[mxstanl]

I had previously posted a question on how to remove a center speaker panal in the dash to help find the source of a metalic sounding vibration noise. After 941 miles on a Southwest Co. roadtrip, we have a bit more information on the noise. In certainly does come from the center of the dash, but not necessarily the top speaker area. Maybe just heard a bit more through that grille.
I wanted to give a bit of background, a while back on a trip for mainenance, they replaced the Interior Air Filter. The noise appeared after that service. It has come and gone and like all good noises is inconsistant. It is annoying of course. I am looking for ideas on how to search for the issue. The service dept. could not locate the issue, last time I was there. Again it comes and goes so I don't blame them for it. If I lower the glove box door, it seems I have a bit more intense noise when sitting in the passanger seat. From the driver's seat it sounds like it is coming from the center speaker area or within 6 inches below that center speaker. If I pointed at where I thought it was coming from it would be the top vents in the center dash over the radio unit. My question is where the interior filter replacement filter is located and if any clips or anything related or touching that filter might be causing this noise. Of course any other ideas on what it might be or troubleshooting the issue would be appreciated!
Thanks in advance,
Mark

[BillAileo]

Check out Art's posting of instructions for replacing the cabin filter: http://www.volvoxc.com/resources/how-to/cabin_filter_removal/index.php

[JRL]

Volvo glove boxes rattle, they all start at one point or another.
You need to first to to shim the door.
Place some furniture felt strips on the edge of the glovebox door so it can close tightly and you can't push it in and out, even a little.
That may do the trick in itself, if not the door has to be fixed by the dealer, there's a trick and I do not know what that is...