sometimes I get Vibaration/shaking/wobbling only upon acceleration starting at speed 40 and up,

the Vibrations/shaking/wobbling is gone as soon as I let go the gas padel.

No Vibrations/shaking/wobbling at any speed if not pressing on the gas padel

sometimes on the highway cruising at speed 70, suddenly starting shake for 5 minutes then the shaking stops.
What is so strange that the Vibrations/shaking/wobbling does not occur always, sometimes at occurs every day for week or two

currently, its running very smooth, however two weeks ago there was some Vibrations


its been over a year experiencing this issue,

Any hint to this Mystery

Car Info 2013 VW Jetta, 2.5 SE; 90,000 Miles