Some people saw the camouflaged Ferrari pictures in the News section and highly doubted that this is a Porsche.
Kudos to the Porsche people if they were really that clever to use a Ferrari body as a camouflage.

I want to ask those people a simple question:

1. why is this Maranello camouflaged, there is no reason to do that ?
2. why the long exhaust pipes in the rear which don't look OEM ?
3. why should Ferrari test a mule in the Stuttgart area, next to Porsche Ludwigsburg ? Ferrari has no production in Germany. The pictures have been taken 200 m (!) from Porsche Ludwigsburg.
4. did you know that Porsche used for example Mercedes ML bodies for secret Cayenne testing ? Why not doing the same with a Maranello body ? The Maranello is big/long enough to store all the necessary equipment and prototype technique.

Porsche never acknowledged that they plan a 4. model range but it is almost sure that Porsche wants to expand their activities and the rumored Grand Tourer would be a good start to do that, besides the upcoming Cayenne.

And a final personal word: trust, we know what we're talking about, even if we cannot always prove it to you.