Strange noise - Help !!!

[g60leigh]

I have a strange grating / whining noise coming from the rear of the car (I think)
it only seems to happen when I am up to speeds of around 70mph and the pitch changes as I accelerate. it goes off if I take my foot off the gas.
I thought it was a dust guard catching the brakes as it has that metallic ring to it, but I have checked all of them and they seem clear.
I have had a good look under neath and cannot see any rubbing.
I haver serviced the haldex and checked the rear diff levels and all are fine.
I am starting to wonder if it is a worn engine mount that is causing some noise at the rear as the engine rocks under load.

has anyone got any suggestions??

Thanks and please help!!! LOL

 

[s3dave]

maybe the heat guard as dropped or loose and is rubbing on the exhaust..

 

[g60leigh]

I have looks at the heat shield and cannot see where it would be catching, if anything it sounds as though it would be catching the prop shaft.