Since August and through January 31, National is running a free rental day for every two two-day rentals. They are also running a status match offer. (Hertz Is also offering status matches through January 31).
Million Mile Secrets flags that Avis has gotten into the 1-2-Free Game as well: a free rental day after every two 2-day rentals through June 30, 2012. Registration required. You can’t redeem in the New York area, can earn a maximum of six free rental days, and won’t earn those days if you choose to earn miles for your rental. You can’t double dip with Avis First, either, but it appears to me that you’ll still get credit in a Corporate Awards account.
For one-day rentals, I credit Avis to my Virgin Atlantic account, no coupon code required and you get 1000 miles for the rental. That’ll eventually mean Virgin Upper Class for me (with big fuel surcharges), though you can also redeem 6000 miles for an intra-Hawaii one-way flight.
On a three-day or more Avis rental I still like the 3000 mile US Airways bonus. (have to use coupon code MUAA044 and provide your Dividend Miles number with the reservation.)
The US Airways 3000 mile offer runs through March 31, though it’s been extended before. Also through March 31, you can earn 2000 US Airways miles on a three-day rental with Dollar and 1500 US Airways miles on a two-day rental with Thrifty.
What other hot rental offers are out there?