Hi I was wondering if you could help me I have a Vauxhall Insignia 2-l Bi-Turbo and I experienced quite severe vibration after 70mph. I have had all wheels balanced and even swapped front to back. I took it to Kwik-Fit who advised me me that it may be any rotational part. Just wondering if anyone else has experienced a similar problem ? The vibration also occurs when braking quite hard. Could this be due to imbalance brake discs? Or maybe drive shafts ? It really drives me mad please help!