vibration on 1999 Mercedes-Benz CL500

I get a vibration that you can feel between 40mph and 60mph. It is at it's worst at 50mph. The tires were checked for balancing and that was fine.

1 answer 1 comment
Where do you feel the vibration? Does the steering wheel shake?

My initial impression is to have the wheel balancing checked again, perhaps at a different service station. Sometimes balance equipment may lose proper calibration and may make tires seem OK.
these cars are very tire sensitive; some brands of tires
just do not work on this vehicle. the tires you have may not be defective; just not the best.