Couple of thoughts.  First people, particularly children, are getting larger (wider), at least in the US.  If Ferry's formula that the 911 must have rear seats is to soldier on, then the car must get larger to accomodate the larger people who will sit there.  Second, the larger wheelbase may be necessary for the cabriolet's metal folding top, which I believe has been confirmed? Did we not see spy photos of the folding top with a much larger covering tonneau? 


--

Carpe Diem--life is but a crack of light bounded by eternities of darkness (Nabokov)