I was thinking back on some of the repairs/maintenance that I have done on my car, and one incident in particular came to mind.
I had been experiencing an annoying chirping sound from the front end that sounded like a flock of little birds when I went down a gravel road. I had sprayed all kinds of lubricant on the control arm bushings, but the sound never went away.
One day as I was doing something under the hood for which I think I had removed the air filter box and intake, I happened to look down at the control arm mount and I noticed a foreign object. When I was able to extract it with needle-nose pliers, it ended up being part of the metal clip on top of the air filter box which holds it closed (which was missing). It had somehow fallen through the engine and landed in the small space between the outside of the control arm and the inside of the frame mount.