Not sure if this helps at all but, but we believe my NS driveshaft has had it. Any revs higher than 3500, and feels like the front wheels are going to fly off ! The massive vibrations come through the pedals ( throttle most), and obviously the steering. Because of other vibration issues, not sure how long this has been going on for. There is a lot of lateral play in the driveshaft, compared to another car checked for comparison. Replacement being put on next week, hopefully this is the cure. If not, the driveshaft can be returned. BUT, ive been warned could be a diff problem. All seems somewhat unusual to me, as never really mentioned on here. Everyone keeps telling me " its the way i drive !"