2001 Scenic 1.4 Rear creak (suspension?)

During the last month my Scenic has developed a creak at the rear. I think it's on the near side and is noticeable going over speedhumps. I never drive over them fast though so the car is not thrashed. I tried squirting Wd40 on the lower shocker bushes and around the arm bearings but it made no difference. The wheel looks ok without any major lean. If I push down on the rear bumper it is there as well. Car has done 66k.

Haynes doesn't have a very good drawing so not sure what it might be. Any ideas?

Thanks.