Clinking noise on offside rear suspension

Hi people, maybe someone can shed some light on my 2006-7 20 tdi A3 s-line problem. I'm getting a sort of metallic clinking rattily sound when hitting small bumps at speed on the offside rear suspension, also if going over speed bumps it rattles as the rear skips over. It just flew the MOT, & when I had new tyres fitted my mate couldn't find anything causing it. It's only audible when I have my window down. I'm at a loss of what's causing this rattling sound, all my exhaust baffles are perfectly intact, so I ruled that out. The car still handles the same too, it's doing my head in!!
Thanks in advance guys or girls.

Just an update on my rattling tractor! The stealers changed a wheel bearing & sensor last year, they left 1 of the tension springs off the inner brake pad! The freaking thing been bouncing around all that time! It's slightly warped my rear disc too, but how do I prove it?? I took the calliper off myself to rectify their F**k up!
Not a clue" I wonder if my car has a 5 star NCAP rating lol!
WATCHDOG????
HA HA!