National Car Rental is running a promotion between now and January 31, 2013 where you get a free day’s car rental for every two, two-day rentals of a mid-size or larger vehicle. If you’re planning on traveling during the holidays with your family, this could be the deal for you.

To qualify, simply join National’s Emerald Club (their frequent renter program) and rent a mid-size or larger car twice during the period for a two-day or longer stay. You have until June 16, 2013 to use the free days you earn.

Other benefits of joining the Emerald Club include being able to bypass the car rental counter and go directly to the car lot to pick up your vehicle. You’ll also earn points for every rental that can be used for car upgrades, frequent flyer miles, and hotel rewards.

National Car Rental: Rent Twice, Get One Day Free