I've got a V with the auto dimming mirror. There is about an 1/8 inch of play vertically from the window mount when I push up on the mirror. This is not play in the ball socket. If I follow the windshield mount from its lowest point up towards the LKA camera housing, the mirror mounting is loose. I can push on the top part of the mounting and it moves up towards the glass that 1/8 inch. Is this normal? I think mine has always been this way.
Most mirrors have an allen head set screw in the bottom of the mirror that snugs up against the baseplate that is glued to the windshield. Check on the bottom of your mirror and see if you can see the set screw. If so, tighten up on this and it should pull the mirror up against the glass.
It could be a torxs head set screw (star pattern), that's what's on mine. A couple turns will secure it...