Alright, so I just bought a 2002 Mustang GT 5 speed and there is a knocking noise coming from the rear end. I took all the seats out and everything to see if that was the culprit. The knocking happens when I go over bumps or take off in reverse or forward in first. It doesn't knock while driving on smooth road only going over bumps or pulling out in first or reverse. I literally took all the seats out and spare tire. There was nothing in the cabin that was making the noise. It sounds like its coming from below right behind the back seats. Any ideas?

 

You'll have to lift the car and check for worn bushings, loose pins/bolts, pin/bolt eyes. These can all be found on shocks, lower and upper control arms, sway bars, etc.

 

Well I found that it was the right rear upper control arm. The bushing was shot therefore the control arm was rattling around. I ordered AJE racing adjustable UCA's I'm going to put them on tomorrow. Thanks for the help!