Over the past couple of weeks my QTS has developed a slight handling issue. When I go around a roundabout or a hardish right hand turn the rear of the car feels vague and a little unsteady. The rear has also developed a knock which sounds similar to the exhaust hitting the chassis although on closer inspection this doesn't seem to be the case. I got the car up on ramps yesterday and can't see anything obvious other than a slight exhaust blow and the rear diff which seems to of sprayed a little oil (will post pics in a bit). I checked the springs which seemed fine as I feared one had snapped. I know bushes can be an issue but this seems to of happened pretty suddenly which I wouldn't expect from worn bushes?? Anything I should check?