You need to go to the Porsche online parts catalog. Look up in the ventilation section and you will see thewater drain tube diagram. If you can find the drain outlet under the car, part # 16, you can blow compressed air and see if you can make the condensate to drain.
Here is the link. Select the model and year of your car.
Porsche Original Parts Catalogue - Parts and Diagnostic Information - Porsche Service - Dr. Ing. h.c. F. Porsche AG
Good luck.