My car makes a rumbling noise at low speeds, and squeals at a full turn. The rear suspension looks like it is sagging.
The rumbling at low speeds may be coming from a tire. The squealing noise at full turn is most likely a serpentine belt for your power steering pump that needs to be adjusted or replaced. The sagging rear suspension could be due to normal wear and tear, or the coil springs for the rear suspension may have broken. I would ask for assistance from one of the mechanics at your mechanic to help diagnose all of your concerns, perhaps beginning with a diagnosis of the squealing noise at full turn.