interesting point about the rear spoiler, a good friend of mine has a Carrera Turbo, his dad used to race with Porsches in Italy in the 70s. We were talking about the peculiar ducktail in one occasion and I remember his dad saying that sometimes it's hard to set the spoiler properly, the risk being some important understeer in certain situations.
I always got the impression that Porsches are well balanced cars (in my humble experience I have to say that the Cayman S actually handles better than a 911, but it's kinda deliberately not better..), so tweaking with them would be a bit sacrilegious, if you know what I mean