Don Y

Hi Guys, I had the same problem with my passenger side mirror on my 2004 RX330. I'm not sure it's the same as your mirrors but I would expect it would be similar in design. On my mirror, there is a small plastic access door on the under side of the mirror (not the mount). The access door is removable with a small screw driver (cover the screwdriver in tape to prevent scratching the door or mirror case) the access door has a very small slot where the flat screwdriver will fit. Twist the screwdriver and the access door will pop open off the mirror. Once the access door is removed then you will see two recessed screws going up into the mirror case (mine two hex head type screws). Use a hex key to gently tighten the two screws (don't overtighten). Once the screws are snug then the mirror will be tight on it's pivot again. Replace the access door by snapping it back into place where it was removed. Hope this helps everyone in this old posting! :)