Where is the location of the donut? Does the car vibrate alot on idle?

Perhaps, motor mounts are shot and the engine's torsional vibration is being transferred to the donut.

These are "shot-from-the-hip" hypotheses and are in no way to be construed as "expert advice" (the techs will probably respond later).

BTW, I don 't know much about your area, but my dad attended Vallejo College many, many years ago...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car