Might not be literally, if you're only counting Manhattan (and depending on the time frame). I would venture to guess it might be in the hundreds of thousands per day in Manhattan. Only 332,000 commuters (I assume this is per day) commute to Manhattan by car: http://wagner.nyu.edu/files/rudincenter/ManhattanCommuting.p..., and I would venture to guess an even smaller number commute within Manhattan by car.

But counting all five boroughs, I am sure it is literally millions per day. Car ownership/use/commuting rates are much higher outside of Manhattan.