[tame3902]

Of course, it becomes tricky to decide what belongs to a factory or not if you look closely enough. And comparing factory sizes is something inherently silly. But I think that in a capitalistic society the land area owned by the company is a good first order approximation. If they wouldn't need it, it would be better for them to sell it.

But in the case of the Volkswagen factory the points you mention lead to something interesting: The city of Wolfsburg was created just before WW2 to house the workers of the factory created at the same time to produce the precursor of the VW beetle. Even today the city is dominated by the factory: it has a population of 120,000 and 60,000 work in the factory. So under a loose enough definition of "factory", the whole city of Wolfsburg is part of it.