Water in rear floor

I just bought a 1995 Mercury Sable. Twice I have noticed the rear floor soaked with water since we have bought it (2 weeks). I am afraid there is something wrong with the doors. All four doors have white deposits on the molding and some of the metal in the interior is rusted. I hope there is no mold! Could the vapor barriers need to be replaced? Or the molding? How do I find the leak?

Does it have a sunroof?

No, there is no sunroof.

Hmmmmm, I’ve owned literally dozens of Taurusables and never had one leak into the rear floor like that. When it leaks, is it parked on level ground with the windows up?

My guess is that you have a leak at the back window or around the trunk lid. On a dry day put someone in the trunk with a good flashlight and flood the back window and trunk lid with a hose.

The first time there was water in the passanger’s side rear floor and I noticed it right after we bought it. It was parked on level ground then, but I don’t know if the windows were up. From the last rain (where it was parked on level ground with the windows up), I checked and there was water only on the driver’s side rear floor. I am going to try the hose trick to see if I can find any leaks…

Ah Ha! Thanks for the trunk tip! I looked in the trunk - the carpeting is dry but under where the tire is there is standing water. The car is on just enough of an incline that the water runs into the back. How can the wheel compartment be wet but nothing else? Would it be easier to just drill some holes in the wheel compartment to drain the water? The trunk lid sits a bit low when the car is shut, so I imagine the “correct fix” may take a bit more work than fixing the gasket…