My car only has 34000 miles.
Most of the time when I get in to my car and sit down, theres a loud creaking sound from the rear. Or if I put something heavy in my trunk. It's not the lumber sound so I don't think it the mounts. And it never happens while driving. When I got over bumps the ride feels fine.

Someone told me to spray lithium grease on all the bushings in the rear. Which I have not done yet.

Does that sound like it might fix the problem or is more of a worn out struts?

The grease will take away the noise. It is the mounts drying up. Happens on mine.

Edit : It is the bushings drying up.

Ok thanks alot, it's been driving me crazy.