My car made a poping or squeaking sound, but also a rattle like something was loose. I haven't driven the car very much since driving from Naples to Panama City. My local delaer has some parts on order. something related to the rear spring and bushings. They also said they were not sure exactly what was needed to fix the problem and once they get the parts they ordered and tare it apart they might need some more parts. They wouldn't know until they take it apart. I don't know exactly what parts were ordered. I'll post an update after they work on it. I'll have them explain exactly what was replaced. I know this doesn't solve you problem, but hopefully they fix it I'll know exactly what was wrong.
See my post under "Squeaky Rear End."