Could this be a coil pack breaking down, i know the weights were removed. the wheels were then sprayed, tyres put back on and Brand new weights were fitted by superTracker which are a well established wheel setting specialist.
Balancing normally would get a wheel wobble on the steering even traveling at a constant speed.
Never had a coil pack go, must admit, does seem simular to slight misfire and makes the car like its "shivering" being a way of describing it.
What to do!!, who to take the car too, Vw for a diagnostic, or Supertracker??? .im sure its not a buckled alloy.
If the alloy was buckled im sure id get a constant vibration on the car whilst travelling.(like being on a push bike with a buckled wheel) oh those good old days.!!
Electronic misfire,under hard accelaration, cant rule that out. Power seems to be there but id say not a crisp as it has been.