Hemmings Blog on the history of New York City and automobiles:

The pairing of the automobile and the narrow, teeming, crowded canyons of New York City is endlessly fascinating. The Standard Catalog lists 334 different manufacturers based in New York City (most of which, surely, built no more than one or two cars, if any), but beyond that, the Big Apple has a history of dealerships, driving, navigation, cab riding, and automotive legislation all its own.

As Just A Car Guy mentions, 334 is a lot of manufacturers.
I love New York.