HI Jonathan and Robert "The discs are identical. Yep, all replaced at the same time The pads are identical. Yes, replaced with the discs The retardation on test rollers is vey similar (even though you've already thought about that on the road). Yes, passed its MOT with no referrals The wheels are running freely both hot and cold. Seemed to be OK when the car was on the ramp, not tried that when hot, but a "hand test sugggests that none of the wheels are running hot. There's anything from the ABS or similar on the diagnostic analyser. Do not know whether this was checked at Service/MOT It's mentioned in any Vauxhall or Opel forum. No idea, this the only forum I use "I would rather think it would be the stability control that caused this" Could be, I don't normally notice it, but it does not seem to like spirited driving over a tight serious of bends and dips, the back can get seriously out of shape. Answer : slow down!!