I have just bought a '98 Omega 2.5 V6 manual Tourer estate. Car fine except that when I get to 70mph and take foot off throttle, between 68 and 60mph the car body vibrates quite badly - this stops at below 60 and as soon as I accelerate again. Car has just passed MOT at reputable garage so wheel-bearings (first thought) should be ok. Dealer suspected exhaust but that checks out. Anyone any ideas/experience? John R