I have a rattle coming from the passenger side of my car. Best I can tell it's from where the dash meets the vent. If I put my hand on either the rattle stops.

Is there a way to secure the vent? It seems like it's not bolted down (I can wiggle it side to side) but can't tell for sure. I've put some foam weather stripping under the dash side cover to hold it more securely but doesn't seem to help all that much.