The old S8 is having a bit of a Wobble

[Nognar]

Good morning all,

One that I hope you may be able to help with.

The S8 has a strange Wobble!

At 70 to 80mph I can feel a vibration/ wobble coming from the underside of the car that you can feel through the floor/ seat. It feels like a mount/ rotation/ driveshaft/ engine is wobbling a little when going along.

Its odd, noticeable and constant as I drive so I was wondering if anyone has had similar and can point me in a direction here.

To cover a few questions off, this is not brakes or suspension and I do not get anything through the steering. Road surface and condition do not make any difference. All the wheels have also been balanced to try and resolve this problem as it was my first thought. Tyre pressures also checked and the tyres are all good, reasonably new and the same brand all round. Recently passed the MOT with no advisories and all the suspension arms and bushes are OK too. Finally no clunks or bangs, no drivetrain shunt, nothing excessive or noticeable when I just rev the engine and the gearbox has been fully rebuilt a year or so ago.

The car has now done over 200k so I suspect something worn/ old as the problem was not sudden but has come on over the recent month. Not sure if this could be the propshaft or its bearing/ mount getting a little old?