I just noticed it. It seems that Porsche copied some of the design characteristics of the Alpine A110...The Cayman is more like a modern/retro design A110 http://www.linternaute.com/auto/diaporama_legende/images/alpine1.gif http://www.edmunds.com/media/roadtests/firstdrive/2007/porsche.cayman/07.porsche.cayman.act.1.500.jpg
I think there are just some similarities, from that angle. I seriously doubt Porsche concsiously copied it.
its just occurred to me that porsche put a roof on a boxster and gave it a 911esque roofline edit for poor typing
that's like saying Slayer copied from Jimi Hendrix because both use distorted guitar sounds! It's in no way a copy!