Anyone have an audible rattle from the passenger seat when someone is not sitting in it? Not just the visible vibration but an annoying ticking/rattle sound (along with the seat vibrating visibly). I can usually get it to go away temporarily by adjusting the seat back and/or moving the entire seat all the way to the back most position but it comes back after a while and I have to fiddle with it again. Anyone know a fix? I am out of warranty so I'd like to avoid any dealer business if possible.