So... When was the last time that you cleaned out all 7 drains?
 

I've found that spring and fall is the best time to service my Boxster -- oil-change and such. An important task is cleaning out the drains so that water doesn't seep into the cabin and cause mold and that funky damp moldy smell. The other simple task is vacuuming any leaves and debris out of radiators. Doing this before you park, or put away the car for the winter will help to prevent issues while it sits.

1) Find and vacuum out all 7 drains and the areas around them. If you don't find all 7, see this thread.

2) Vacuum out any leaves from the radiator compartments. I've found a couple of spare tubes (without the extra wiring and plugs used by the carpet beater) from a household vacuum cleaner work great to reach into the back corners.

Both of these important, but simple tasks are often overlooked.

Thank you. Great advice

I see many people focusing on the drains around the convertible top (Boxster) but the ones that seem to take on the most debris and not drain well (Boxster & Cayman) are the ones under the front plastic cowl around the battery tray area. Like you, I can't stress enough how important it is to clean out these drains periodically.

7 drains just like the 7 sins