A long stethoscope is not a bad idea. I think the Alinement Shop has microphones now for clunks an noise detection.
As stupid as this sounds, instead of just throwing parts at it when you don't even know where the sound is coming from, go to the parts store, get a small funnel, 10 feet of 3/4 hose and a load of zip ties. Put the funnel on the hose, put that where you think the noise is coming from, zip tie the hose out of the way all the way to the inside of the car, usually threw the window. Now drive the car, do what you need to make it make the noise and put the hose to your ear. Just keep moving the hose until you hear it the loudest threw the hose. Cheap, easy, reusuable and it works. You might only hear it threw the hose when it's right next to the culprit. just remember to put an earplug in the other ear. Let me know if this helps everyone out.