I bought the car in August of 2015. It usually does not rain a lot in Texas. These leaks happened either late 2015 or early 2016.

While diagnosing one leak, found another leak.

1st, I removed the passenger seat. Had to use a propane torch, WD40 (light oil) and vise grips pliers to remove one broken, rusted bolt. I pulled up the carpet just enough to access the floor. It took two weeks for the carpet & padding to dry. I sprayed disinfecting spray on the carpet and padding.

I poured water through the windshield wiper cowl to simulate heavy rain. Water drained through FACTORY slots (holes) near the seat belt anchor bolt INTO the floor where rear passengers put their feet. I raised the rear of the car, drilled two 1/4 inch (4-5mm) holes under the body where the mystical drain holes are supposed to be. When water came out the drilled holes and not into the car, I sealed the factory slots/holes.

2nd, I removed the entire back seat, the back-seat side panels, speakers, etc. to access the fender well. I poured a bottle of water in the hole where the rear window glass rolls up to meet the top's weather strip near the body of the car. While inside the car, I saw water seeping between the factory welds of the wheel well. I spread silicone sealer thick and heavy all along the seam of the wheel well. This stopped water from entering the car and collecting under the back seat. I then took the car to a welding shop to repair the rust holes in the floor under the back seat.

As of Nov 30, 2016, the carpet has stayed dry. I now have to be sure the weatherstrip is in proper position when rolling up the rear windows.

Water seems to be leaking between where the glass window joins the the vinyl top of the convertible roof. It's just a slow drip leak but if left unattended in heavy rain the liner behind the back seat fills up with water. Which is especially not good because all the stereo amplifiers for the Mach audio system are right below it!

Car was fine until late 2013 at around 100,000km, always garage kept while home. Parked outside for around 6 hours of a heavy rain storm and ever since then the leak has never stopped.

Tired of Ford dealerships saying they have never heard of this problem when it is out on the internet everywhere when you type in 2004 Mustang Convertible leakage. How many times does it have to be listed before ford fixes the problem. If there is a defect in a product the consumer should not have to pay. My convertible top actually is leaking there seems to be two stupid little holes that are under all the material for the convertible that are of no use because they are to be covered so rain does not go down the hole and drain onto your floor boards or the area where the convertible top sits in when put down. Why would you have holes that are to be covered and then the covering comes off and you have to pay dearly for the holes to be covered back up. Come on Ford help us out and recall this defect.

I have a 2004 Mustang convertible that was like brand new with very low mileage when I purchased it 2 years ago from an elderly lady that only drove it sometimes on the weekend. As of a few months ago, I started getting rain into the back floorboard behind the passenger seat only. It gets really wet!!! I know the convertible top is not leaking. I covered it for a few days that it continued to rain with the corvette cover for our corvette as it has prevented it from leaking in previously. Strangely enough, the last time, it still got wet! I took it to the Ford dealer as I thought they would have seen someone that has also ad this problem but they said no. I went to the best upholstery place in town that also does beautiful convertible work and he thinks it could be leaking in somehow around the rear glass window. It seems like water would also get into the trunk if that is the case but the trunk stays bone dry.

Has anyone had this or a similar problem??? You may contact me if you have a solution. Thanks!