After reading the comments on Andy's thread I think I too have a propshaft problem. Ever since the car was fineshed ( 2 years ) when you get to 50 / 60 mph I get a vibration that feels like your sat on a hammer drill which gets progressively worse the faster you go. There is no vibration through the steering its through the seat. Thought it was a buckald wheel so changed them , no success, changed one of the driveshafts still the same, checked the uj's all OK. Bit heath robinson but put the car on stands and ran the car then wedged each wheel in turn to see if the vibration stoped , no joy.
After all this am I right in thinking its the prop?
Just after some advice, confirmation before I dissmantal the car to take it out