W202 vibration woes

[jjrodger]

I'm looking for possible cause of vibration in my W202 C240. The car has sports suspension and AMG 17" wheels.

There is a vibration in the wheel and throughout the car at 60mph plus. It is especially bad at 90-100mph. On a trailing throttle it is worse. Braking makes no difference and it is not especially noticeable under braking. I discovered that the steering damper had failed and this was replaced last week. The vibration is no different.

I have had the wheels balanced twice. No change.

I figure the steering damper is not the cause, although its own failure may be a result of the vibration.

I am not convinced it is caused by warped discs as braking makes no difference.

I can feel it throughout the car: the wheel vibrates, I can feel it from my leg resting on the transmission tunnel, it is in the seat base, and the sun visor vibrates.

I really need to solve this one as it is spoiling a great car. Ideas very much appreciated.