Silly but simple.
Sun visor not properly clipped into holder.
Glass in interior driving mirror slack. This annoyed me for days, It did not seem as if it was in that area caused vibration/rattle noise at certain revs. A new mirror was only warranty claim, except 2008 heater recall, for nearly 40k miles of my ownership. All FL2's (3) Gone
2011 Mercedes C180 CGI Gone
FL2 GS Auto SD with heated leather, factory tints, alloy spare and a few other bits.