As know you told if the alarm box under your seat gets wet and shorts out, it will need to be replaced along with new keys. A $1500 repair by Porsche. So get that water out fast and dry it out. If you cannot track down the leak, in the short run buy a cheap car cover from ebay. $35-$50, it will keep you Boxster dry.
Now, I also have a leak on my drivers side. It was where the water drains from the foam tray into the funnel under the foam tray. If you remove the 2 plastic screws and lift up the foam tray you will see the plastic funnel which exits the body into the fender well and attaches to a tube. That void around the funnel goes into a panel that goes into the cabin behind the seat. Not sure why they did that. But they did not put a membrane there for a water stop. Instead the glued this piece of rubber installation that goes from the floor up to the foam tray and maybe be part of it. I found this because this installation was wet, so wet the glue gave way and it started leaking inside. I live Florida so you know how wet it gets here. You can fix a leak once you know the source.
