Rent a car in New York is a tricky business, with its own quirks. First, figure out the insurance. Read carefully what's included in a regular policy, and think about whether you need an extended one. Then, fuel. It's usually cheaper to fill up your own tank than to take the "full tank" option from rental companies. And third, fines and screw-ups. When you pick up the car, inspect it properly so that all the scratches and dents are recorded, otherwise you'll have to pay for someone else's screw-ups later. By the way,
here's where you can come up with ideas for a three-day trip around the city.