I'd take what's in my garage. Because, once those fat cats get their poop together and start policing the people that're left after the distaster, they're gonna ask you where you got that Ferrari from.
And if there really is no one left in the world, what's in my garage will be faster than any car I can steal anyways. And I'm gonna find the smoothest, longest road I can, and do something I don't have the nuts to do in the real world.