Steve,
I was just ready to post a thread on the same subject. I had a strange squeak that was most apparent when I was cruising slowly down a bumpy road. To the knowledgeable ear, it would sound like it was from the rear suspension, perhaps a shock bushing, or the anti-sway bar bushing. It turns out that it was the rear clamshell bump stops rubbing against the bolts on the latches. I greased the rubber bump stops as well as the latch catch mechanism where there is metal-to-metal contact. Voila! No more squeek. My blue car had the same issue and it was fixed.