I got the same problem. It begin really occasionaly, and now it squeek every time I'm doing slow manoeuvre in a parking. I was going to start a thread about that today, When I just saw this one!
Could it be something else too? like a Dryed bolt-joint ?
Is there a check you can do to be sure where it come from?
Could that be also the source of an other noise when I sometime stand-up from in the car, as the suspension raise up, I get a harsh noise?
Thanks