[BimmersInGA]

I have a 2002 Boxster (98K miles) and last night we got a little over 3 inches of rain here in south Georgia. After the rain started to let up, I heard my alarm going off. But it wasn't normal. It would sound for a few seconds then stop for a minute or so, then sound again, then stop, and so on. I went outside turned on the key to shut it up. I noticed that the red light on the dashboard stayed on even after switching on the ignition - it's never done that before.

As soon as I switched it off and got out, the alarm started going off again. So I decided to disconnect the battery and deal with it in the light of day.

This morning I reconnected the battery and red dash light stayed off, so I thought it was resolved. But when I tried to start the engine, I got nothing. All the dash lights come on and the oil monitor does it's thing, but there is no reaction to turning the key to the Start position. No clicks, no nothing. I thought maybe the battery had run down, so I tried jump starting it. No luck.

Shortly after I bought the car, we had another downpour and the next day I found the carpet on the floor behind the passenger seat soaking wet (US spec, driver on the left and passenger on the right). I did some research and learned that there is a drain on either side of the well that the top lowers into. It turns out the drain on the passenger (right side when seated in the car) side was clogged. I cleared and checked the drain on the other side. It was clear, but just to be sure, I poured water into both drains and it drained out nearly as fast as I could pour it in.

So I checked that area again and it was dry. I also checked all the carpet in both trunks and all around the cockpit. Then I found the carpet on the floor behind the driver's seat to be soaked. There was actually standing water in the floorboard! From what I've found researching, the engine computer and/or alarm controller live in that area, which would explain the weirdness. So what's my next move and where could the water have come from?

I soaked up as much of the water as I could with a towel (several towels, actually) and then pushed the car into the garage where I opened everything up and set a fan to blow on the floor behind the seat. Hopefully it will dry out, but I am assuming that I'll have to remove whatever electronic brains are in there to try drying them out. Is it as simple as removing the seat and pulling up the carpet, or is there a specific procedure to access those components?

The best case scenario is that everything dries out and I'm good to go. Worst case is fried electronic brains. If that's the case, what am I looking at to get them working? I'm a fairly handy DIYer and don't think I'll have too much trouble swapping out the controllers - if it's that simple.

Finally, where could the water have come from? Assuming the drain in the well for the top is clear, what are the other possible entry points? I have owned and worked on BMWs for about 15 years and they are notorious from water leaking from inside the doors, so I checked along the bottom edge of the driver's door, but it's dry. There is also no moisture around the firewall or elsewhere around or behind the seat. It all seems to be only on the floor behind the seat. Is there another drain somewhere that I don't know about?

If a computer brain is fried, can it simply be swapped? And what would be a good source for a replacement?