Consolidators

Auto Escape - Worldwide reservation center, for any country. No online booking.
autoescape.com

Auto Europe - Provides car rentals, flight tickets, hotels, and specialty cars. Offers prices in a number of currencies. Cellphone hire available to US residents.
www.autoeurope.com/

BreezeNet - Online booking of discount rentals at major airports, worldwide.
www.bnm.com/

Car Rental Express - Offers online rentals from independent agencies in many world cities and airport locations.
www.carrentalexpress.com/

CarRentals.com - Offers worldwide service from several suppliers' inventories.
www.carrentals.com/

Holiday Cars Direct.com - Providing rentals multiple countries including USA, Spain, UK, Portugal, France and Italy. Online booking available.
www.holidaycarsdirect.com

Ofran Holiday Autos - Broker, providing vehicles at many locations worldwide, providing information on destinations and an online reservation system.
www.ofran.com/

Pinpoint Travel - Car Rental - Find discount car rentals from multiple sites.
www.pinpointtravel.com/home?tab=cars

RentalCar.com - Worldwide reservations. No online booking.
www.rentalcar.com.au/

Skycars - All-inclusive online car hire for the USA, Europe and Australia.
http://tylerschnaidt.com/blocked/nph-index.pl/010110A/https/www.skycars.com/

Transhire World Wide - Offers car rentals worldwide.
www.transhire.com/

U.S. Rent A Car - Car hire consolidator offering fully inclusive USA car rental services to UK and European tourists.
www.usrentacar.co.uk