After a bit of research, found out that the image is by a 16 year old in Stuttgart - Click here for his portfolio - Although it does look a lot better than some of his other efforts.
Maybe he has seen the real thing? or maybe it is the real thing and he has somehow managed to get hold of the pic and is passing it off as his photoshop
It's definately a photoshop, for example the optional 19" wheels are of different size in the two pictures. But it's indeed one of the most realistic ones!
I love the targa idea and can only hope there will be a Cayman Targa... also can someone photoshop the old 914 engine thingy into the design.. (and you might wanna loose those rear side windows!!) IMO http://www.progression.net/~vm011001/images/914-1.jpg