The drains in the Cabriolet top can clog, causing water to leak onto the carpets. Water can also accumulate in the doors, causing various electrical problems.Google+
Car Problem Reports
Porsche Boxster Water Leaks in Cabriolet Tops Due to Clogged Drains
Porsche Boxster Problem
Average Mileage: 40,683 mi (17,000 mi - 75,000 mi)
Visitor, 2003 Porsche Boxster, 20,000 mi
After a very rainy day,the car would not start and other electrical issues were occuring.I discovered a great daal of water under the driver's seat which apparently damaged the ECU which is under that seat. After being towed to the local Porsche dealership,I received the bad news that the repair costs would exceed $2500.00.Fortunately since the warranty was still valid, the dealership and my insurance company agreed to cover the costs less my deductible.There apparently is no mention of these 2 drains and the importance of keeping them clog free in the Owner's manual.The 2 drains in question are located (one each side) in the space the top retracts into when lowered. To locate,partially lower the roof about 1/3 to half way,then grab the rear lower roof edge and lift toward the front of the car.At this time insert something between lower roof edge and the car's body to keep the roof edge raised.I use smething with some give to it and is pliable to avoid any damage to the bodywork such as the plastic container Armorall wipes come in.You should now be able to look about 9 inches into the area the roof retracts into and see the two drain holes.They are about 3/8 inch in diameter,use a shop light if needed as they are really down in there.Now vacuum or hand remove any visible debris covering the drain recess,next using compressed air blow through the drain to clear it or as I do place a shop vac nozzle tightly over the drain hole and suck out any additional leaves etc.The last step is to pour a cup of water into the drain recess,if the drain is clear the water will drain right out on to the floor or driveway. If the car is parked below trees,the drains should be checked pretty often because it does not take much to clog them.Some of the after market manuals cover this drainage situation.
Visitor, 1997 Porsche Boxster, 75,000 mi
Leaky roof, very wet carpet. I've cleared the cowl drains several times, but the problem continues.
Visitor, 2009 Porsche Boxster, 23,000 mi
2nd time an electrical module damaged due to cowl drains being clogged after following recommended maintenance causing thousands of dollars of damage. When taken to dealership I was asked if I ever park my car outside. Where am I supposed to park it? I think this is a poor design and Porsche should be held responsible for damage.
Visitor, 2003 Porsche Boxster, 58,800 mi
1/2 inch of rain water behind and under drivers seat.
After a hard rain the car went nuts. Top tried to open on own while the top was secured. Mechanism got bent. Still under warranty but Porsche of America claimed it was owner negligence secondary to not following maintenance reccomendations of cleaning out body drains as needed. Total cost of $7900.00 to repair. Does anyone clean out drains on a regular schedule ? Where are the drains? Could not find them in any manuals.