Ronald reaves

Cool find.  I'll experiment with that immediately as I suspect that my noise is somewhat more than my find suggests.

Will let you know.  Unfortunately Atlanta, Ga. has few unfinished roads.  -R

it really sounded off yesterday with someone sitting in rear drivers side seat with armrest up or down

Dan. I've not takin it to the shop yet.  I'm trying to verify whether there is an additional similar loose hinge connection first.  And if yours is like mine you can't replicate it just by touching.   You must bounce the seat gently.  I'm searching daily.

Hey folks

I think I found the rear seat rattle problem.  Mine is a 2014 RX 350.   Beneath the rear center seat are 2 hinges which appear near the front of the seat.  The left hinge is tight and snug while th right hinge has a little play in it.....very very little.  But it's enough to get that rat-a-tat-tat metal to metal sound.  I can reproduce the sound by hand by bouncing the seat or by shaking the hinge. The right hinge parts are a bad fit.  But it is still intermittent while driving