I recently booked a car at EWR with Payless for 18.90 day, about $58 total for 3 days (Sun-Weds, Feb 4-7) I've rented from them before, With the monorail down you have to take a bus to the long term parking station to connect with the Ramada van to get to their office at the hotel. It's worth the trouble for the value conscious traveler.
It's curious but sometimes a "Compact" prices lower then a "Economy" car. With the car rental companies being as stingy with FF miles I rarely consider mileage when choosing a rental.
In large metropolitan areas often there is a significant demand for rental cars on weekends from locals without cars, which, of course affects rental rates.
I have found that sometimes the daily rate can be significantly lower if you pick-up a car from a major company at it's downtown location. I've saved $20 a day picking up a National car in San Fransisco, with no charge for dropping it off at the airport.
[This message has been edited by Old Gold (edited 01-28-2001).]