rear suspension making noise lubricated all bushings and still making noise

It could be many things, unfortunately and without hearing the noise first hand or being able to do some basic diagnostic tests or be able to drive the car, its hard to say what the source of the noise may be. Make sure it's safe , get under the car and get a friend to bounce up and down on the car see if you can then hear or locate the noise. Pay attention to the rear shock bushings, sway bar bushings, suspension bushings and exhaust hangers.