Have you tightened the screw on the under side of the mirror? My come loose and the glass shakes, but tighten that screw up every now and then and good as new.
Hey I've been trying to find a fix for that myself for 4 years, couldn't come at paying $200 ea from the wreckers. My passenger side went first as mentioned above but they both wobble now. I'll do the adjustment thing as well & see if it works.