I also have a mirror that jiggles when underway. I think the wind direction and speed are main cause.
I am running out of match books and other things to jam the glass against the housing.
I was also with the understanding that the glass was held to a back plate with velro. When trying to pry the glass off, I pulled pretty hard on it until I chickend out and decided to live with the problem.
I would like to pull this thing apart and replace or adjust the servo as JDUB mentioned. Can someone confirm the proceedure?