Had the same problem in my 04. The driver side rear squeaked with almost no effort. I took it in to the dealership and they told me it was a bad bushing in the knuckle. There is only the one bushing inside the spindle. Chryslers quote was $1800. We picked the rear suspension apart to get to this bushing. Picking it apart was relatively easy. Everything will be held together by the shock, the suspension drops out of the way. The bushing was not worn, but dry. We stuck a grease needle into the bushing and gave it 2 or 3 squirts. No noise since!