http://www.cars.com
2. CarsDirect.com
http://www.carsdirect.com
3. AutoTrader.com
http://www.autotrader.com
4. CarPoint
http://www.msn.com
5. NADA Guides
http://www.nadaguides.com
6. CarPrices.com
http://www.carprices.com
7. UsedCars.com
http://www.usedcars.com
8. AutoNation.com
http://www.autonation.com
9. CarSmart
http://www.carsmart.com
10. autobytel.com
http://www.autobytel.com