Intermittent whine from rear (on overrun)

[Crazy_Ivan]

I'm wondering if anyone can help. I have a 3.0si E86 and an issue has just arisen. After hard-ish acceleration in I'm getting a horrible whining noise from the rear when I lift off the accelerator (I also think I may be hearing the odd unusual 'clunking' noise too but I'm not sure), has anyone ever experienced this? What's the cause/solution? I'm thinking maybe an issue with the diff...
It doesn't happen all the time, only occasionally, which to my mind is even more frustrating as I just know that if I take it to the garage to be diagnosed, they probably won't be able to recreate the problem!
Any help/advice would be greatly appreciated.

 

[Ducklakeview]

Hmm, unusual to get the noise on overrun, if it was the diff, I'd expect it under load. Could be a wheel bearing or driveshaft?

Mike