E90 squeaky noise when reversing

[alijanjan 3]

Hi guys
Having a problem with my e90 where there is a squeaky noise coming from the rear of the car but only while reversing, goes away as soon as I start to go forward. 
Anyone had this noise, any help is appreciated 
It sounds exactly like this youtube video
https://youtu.be/3Dyi3X5bpmU

[jon dee 500]

I'd be inclined to go with the advice given in the comments on that video. Get under the back of the car and with the trans in neutral, see if you can find any play in the rear universal joint. Look for signs of any powdery rust coming from the UJ caps. If you have play drop by a driveshaft shop (Beattys for example) and see if they can rebuild the UJ for you.

 

Cheers...