I have a little vibration in my 240 around 35 mph (no tach) in 4th and 20 mph in 3rd. Larry Bible's suggestion about two flat washers under one side of the carrier support made very little difference for me but you might give it a try unless your bearing and support are new as well. I believe replacing all mounts next will fix my "buzz." I know what you mean about the mirrors!

__________________
Rick
Avid Benz watcher

Previously owned 126's: 2 1981 300SD's, 1987 300SDL, 1991 350SDL,
Previously owned 123's: 1978 300D, 1983 240D, 1985 300D
Previously owned 124: 1994 320TE

Currently:
2004 Toyota Sequoia SR5 206k
2010 Ford Edge 122k
Always looking for the next MB diesel!