I don't think Porsche would even take it. They've already admitted it was a mistake to take a contract like that. Gran Tourismo would take full use of all their cars from their entire heritage. I don't think they would sign any contract with another game to exclusively feature them. I think they'll just license their brand to games such as Gran Tourismo and Forza for a bit.
I forget where I saw it but I read an article or a quote from someone at Porsche talking about it. I wanna say it was around like just over a year ago.