National Car Rental ranks No. 2 and Hertz No. 3 in the annual survey of nearly 13,000 renters.

The survey, which polled consumers who rented cars at airports during the past 13 months, looks at six factors to measure overall customer satisfaction: costs and fees; pick-up process; rental car; return process; reservation process; and shuttle bus/van.

Enterprise scored highest in five of the categories and tied Hertz for the best score in the shuttle bus/van category, says Paula Sonkin, a J.D. Power and Associates vice president.

On a 1,000-point scale, Enterprise had a 770 overall score, followed by National, 757, and Hertz, 747.

National was the only car-rental company that improved on its score in last year's survey.

Alamo Rent A Car's 730 score this year was the fourth-highest, but it was below the car-rental industry's average customer-satisfaction score, 733. Enterprise, National and Alamo are all owned by the same parent company, Enterprise Holdings.

Five other car-rental companies — Avis, Budget, Thrifty, Dollar and Payless — scored lower than the industry average.