Your picture isn't working, but when you say AC drain are you are referring to the convertible top drains? Clogged top drains are almost always the cause of water under the seats. If you park outside regularly, and these drains are the issue I would suggest you buy a set of 987 drain strainers, part number: 987 561 487 00
Thread and diagram of drain locations:
http://986forum.com/forums/boxster-general-discussions/37955-drain-holes.html
