[Captain Ahab Jr]

Porsche may still do F1,

McLaren would be the best partner for Porsche as Andreas Seidel who Team Principle before that he was Team Principle of the Porsche LMP1 programme so Porsche would have confidence of having one of 'theirs' already on the inside

I've heard McLaren now has a German type management structure/practices which hasn't gone down well with the long term McLaren guys

Or Porsche could buy out Williams if they wanted their own team but that would be an extremely long road from the slow end of the grid before Porsche would enjoy any success, assuming Porsche stay in F1 for long enough