Driving in Manhattan should be avoided during business hours, and often during weekend days too. Some neighborhoods have good availability of parking meters, but the city now charges about the same as private lots average rates. That is, Manhattan meters are now generally $3.75/hour which really adds up fast. But after business hours, I would say driving is not a big hassle. There is no shortage of commercial parking that opens up at 7:00 PM for everyone.
At other times, there are many secrets that allow you park for free. Some legal, some not. I stick to the legal, and I have ways to get free parking in Manhattan by knowing all the parking regulations very precisely. And for those who may not know, there are easily accessible & close parts of Queens with NO street cleaning regulations You can leave your car indefinitely for free, just make sure to clean it off every once in a while