The best car rental cards are:
Chase Sapphire Credit Card
Chase Southwest credit card
American Express Starwood card
Honestly, any rewards programs from the Chase or Amex as well as major airlines cards have tie up with most car rental programs and these are often the best or the only way to redeem rental cars program.
The only gripe I have with most car rental redemptions is the fees that the car rental agencies charge. Even for multiple days from or outside the airports, I found there are so many fees that pretty much bring the car rental cost to over 20 bucks per day. Not including the fuel cost which I normally fill prior to return or the waiver of insurance if they are covered by a credit card, it still amounts to much. So all in all,, you are again better off with a cash back card, check for coupons and 10-15% off from the respective car rental websites. Just subscribing to their email option or joining their loyalty programs gives you much better cash back. Also, even if you take the car option, do not rule out services such as Uber or Lyft. These taxi services have nice coupons and discounts online. And if you are travelling to NYC, it would not be a complete trip unless you experience the famed yellow cabs in the city.
Credit Cards Earning Points on Steroids 