I have that same problem too. I tried to tighten the screw under the mirror but it's so rusted and the head of the screw is gone so I can't move it. I think on the inside of the car there is a black plastic triangle that must be removed and then apply silicone around the triangle on the mirror itself. I don't know but I read this somewhere as a solution from Acura's Service Bulletins. If anyone knows whether this is the solution please msg back. I know this noise is really annoying. Thanks in advance.