Until four weeks ago, i would have rated my passat as one of the best,then during a mot, i was advised that the front tyres were going to need replacing. I replaced them two weeks ago fitting bridgestone 235 /45 / 17 to replace old michelins. As soon as they were fitted i noticed severe shuddering from the back end, with very uneven running back tyres goodyear 235 /45 /17, which seemed reasonably healthy. After having front tyres balanced for the second time, the problem refused to go away !! yesterday i consulted premier tyres, who said " simple you need new rear tyres !!! they were duly fitted, all the wheels rebalanced, and,guess what, problem is every bit as bad DOES IT SOUND LIKE SAWTOOTH ? if so what can i have done ??