It is an alignment issue/feature and PASM makes it more noticeable. The cars are set up to turn-in well so while they track straight when there is no cross wind, just a little wind seems to push the car though. Drive a big, slab sided truck or Van and it will not seem as sensitive because the toe in on these vehicles is much greater to 'MAKE' it track straight. Some may prefer this but, in fact, 'sailing' your Porsche is part of the charm when you want quick steering turn in. Next time you get an alignment you should be able to request a little more toe (at the expense of some tire and mileage).

Enjoy, it's all good.