Passenger Seat Rattle Fixt
A while back there was a thread about this problem. I recall the consensus opinion was 'live with it.'
Not this child. Bugd the Sh.. I mean the Pi.. I mean the Fu.. uh.. well it really bugd me. I eliminated the rattle by leaning the backrest as far forward as possible w/o the seat sliding forward.
Near as I can tell w/o removing the seat and dismembering it - the backrest has a spring and/or spring-n-rod mechanism under there and that's what rattles when the seat is unoccupied. With the backrest forward there must be enough tension to stop it.