For more than eighteen months now, I've had a constant knocking sound at the rear. I can only describe it as if I had a large pebble in the boot bouncing about. It would do it all the time with the slightest ripple in the road. Last year the car passed the MOT even with this problem, so I thought it couldn't be anything serious. I've just had it MOT'd again, and it failed on anti roll bar linkages near and off side, and lower ball joint near side. This work has now been done and the knocking at the rear has gone Correct me if I'm wrong, but all the repairs have been done on the front of the car. Everyone who ever sat beside me in the car, and heard the noise, swore the sound was coming from the offside rear area. Just thought anyone who has a similar problem might like to have this information.