I usually take the Hertz points (ZE1 code). I have racked up over 9000 points in the last year and a half. That's enough for about 3 weeks of car rentals. You can also transfer these over to airlines with a 20% cost (600pts = 500 miles) to top up your acount for awards. Most car rental awards thru air/hotel programs don't ahve much flexibility, so I like this option for saving on car rentals when on vacation.