My '89 Lariat has developed an extremely annoying rattle somewhere in the workings of the front passenger seat.

It comes from the seat's lower region, but I can't pinpoint exactly where, even while standing outside the shotgun door, and shaking it by hand while looking for detectable movement from a possible loose spot down below.

Aside from wearing firing range ear muffs while driving, or donating the seat to the homeless, does anyone have any tips to help me track down that boisterous bother?

If so, it would be greatly appreciated!

Thanks...