Found a solution the hard way this weekend to some hard-rain leaks we had into our 2002 SE this weekend.
Symptoms: First noticed wet carpet in the back, and then in the front. Also noticed a wet line in the carpet coming from the passenger-side front door, about 3/4 of the way back from the front.
Wrong Solution: My first guess (got proven wrong) was that the door bulb seals were leaking, so took them off and ran a bead of silicone under them and reinstalled. Guess what, more water showed up in the floorboard while my wife was hosing the car for me.
Solution: It turned out (at least in this case) that water was coming in the window seal right at the rear-view mirror. That'* ok normally, because there are huge drain holes at the bottom of the door which drain the whole steel door shell out. However, with the door open (and you can try this if you happen to be investigating why you have wet carpets), carefully spraying water at the base of the window, a lot of it came out the bottom of the inside door panel which drains right down the carpet. From inside, with the door closed, it looks like it is coming in across the top of the bulb seal.
Inside the door panel (it is held on by the jagged plastic push clips), there is a "Water Deflector" which is a clear plastic cover over the steel door shell held on and sealed by a string of black gooey adhesive. It had come loose at the bottom. I found replacement sealing strips at AutoZone (much thicker) and they called it "Ribon Seal" for installing windshields.
Doesn't take much time to fix, and the seal was around $8. But I'd have paid a lot more for the "how" last weekend!
edit: Here are some pics I took of the repair (other door, same problem) http://www.focaltechinc.com/josh/bon...r_leak_fix.pdf
(1.6MB, Adobe Acrobat)