If you carefully pull the rubber weather stripping from the door sills,

the area behind the interior liner where it contacts the actual metal

of the car can be seen. The plastic tab of the liner can rub in certain

areas and so produces a rattle/squeak. I had a bad one coming from

the drivers side ceiling hand grip area. I got some firm sponge[3/4"

thick] , jammed it way up in the space visible when the weather stripping

is gone and this eliminated the squeak. Also,under both front seats,there

is a plastic housing that covers some wiring......by pressing down on two

tabs at the rear of these housings,they pop off. This eliminated some

more squeaks.