Thanks all, I took it to a BMW main dealer and the diagnosis was transfer box replacement. Now done. £5k ouch!

2010 X6 40d - I'm getting a vibration when decelerating to a stop, when reversing and when doing hard turns at low speed. When driving at speed there is no issue. I've had the engine and gearbox mounts changed. Inner rack arms, lower arms, drop links and track rod ends changed. Recent 4 wheel ...