RAD, I might be having the same issue, but I'm 85% sure that mine is actually just a loose shock. It only happens on the driver's side, hard break, turn, or accelerate. Been this way for as long as I have had it.

https://www.youtube.com/watch?v=g3qmBKTtcCM

 

Initially I also suspected my upper shock mounting.
This is my upper mount:


I found signs of shock mounting rod not centered with previous shocks.



So (before I found the issue with the control arm), I inspected my couple of year-old shocks for above problem, but found none. Then, I removed both shocks and drove slowly around the neighborhood, including speed bumps. Creak remained

 

and here is the reason .. I would 99% guarantee this is your problem

 

Thanks, Slacker. Creak went away after this last alignment, but, yes, bushings would be my next suspension project.