I dont mind so much my mirror shakin, its more when it goes limp and I am left looking at my back seat shakin. This will only happen when Im listening to like some project pat and its really hot outside, but it gets on my nerves.
most mirrors are on two little ball joint things right. well what i done was pointed the mirror down towards the seat then move the bottom joint up as far as it will go so it's pushing against the roof. it still shakes a little but i can see perfect out of. chances are your mirror isn't close enough to the roof to do that or something though