Under padding in trunk and under back seat gets wet when it rains

The actual seating part is bolted through the floor board. You will have to climb under the car.

I don't think it can make from the trunk to the back floor.A better bet would be a leak with the weatherstripping at the back or bottom of the driver's door.

The bottom of the bench seat pushes back to unlatch from the floor then lifts out. You can then access the screws that hold the back padding on and remove those and lift the back out and get in the trunk.

Leaking trunk seal or rear window sealer also check the tail lights are mounted properly and that the trunk is closed all the way

check your window seals and seals by defrost vent. One is leaking

its along way from the trunk to the back seat. check the back window,and the doors, get a water hose and have someone inside check it for a leak. Water in the trunk is usually caused by bad seals at the tail lights. But water in the trunk usually stays in the trunk and spare tire area. If the car has been wrecked, then who knows.

If your concerned that there may be another place of water entry. Find a shop that has a tool known as the "SMOKER" this is a device that produces white smoke with mineral oil or scentless baby oil. I suggest to fill the trunk up with smoke and see where the smoke escapes to.

first thing the rear window seal may be leaking when it rains .this will cause water to get in the trunk and the cable is probably broken or disconected at the handle .ther should be a metal plug in the trunk under the mat u can remove to alow the water to drain out .

sometimes the window weather strip isn't air tight and it could get in your door panel.

sounds like the weather stripping around the door is bad or is torn