I have a 2006 Ford Fusion that is making a very annoying clunking sound in the drivers side rear of the car. This just happened suddenly and is driving me crazy.
what i have done:
I rode in the back seat / trunk area while someone else drove so I could pin point the area. The sound is coming from the area of the shock on the drivers side. I jacked it up, took off the tire and inspected everything but nothing jumps out as an obvious problem. I am hoping someone else has experienced this issue.

 

One of the first things to go are the swaybar links. They clunk when you drive straight, but they clunk less when you take a corner and load the sway bar. Use a tire iron or a pry bar to see if there is play in the links.

 

Sounds like you need a new strut bearing plate. There is a rubber bushing that the strut rod goes through and has a nut the keeps the spring and strut assembled as one unit. The metal insert thats formed into that bushing is most likely pushed though and is hitting the strut tower as the suspension moves up an down. If you can gain access to the top of the strut tower, you can look down the hole, or put your finger down the hole and feel for the strut rod moving in and out of that hole while someone is bouncing the rear of the car, it is not supposed to do that, and would verify the concern. Replace the strut assemblies in the rear should fix this.