Editor's Note: This is an updated version of an earlier story, also reported on "Good Morning America," to correct a calculation error. See details of the correction below.
A survey of the major rental car companies by federal safety officials found that in a significant number of cases the companies have rented cars under safety recall without first fixing the defects.
According to the survey, commissioned by the National Highway Traffic Safety Administration (NHTSA), the big three in the rental car business -- Hertz, Enterprise which owns National and Alamo, and Avis/Budget – since 2006 have let tens of thousands of drivers go on the road without repairing defects.
Due to a calculation error by ABC News, an earlier version of this story, also reported on "Good Morning America," misinterpreted the data on the percentage of repairs and did not give the rental car companies all the credit they were due. Even so, safety advocates say anything short of a 100 percent repair rate is unacceptable.
"The bottom line shows that none of the rental car companies are doing a good job," Clarence Ditlow, executive director of the Center for Auto Safety, told ABC News.
Last November, NTSHA had asked the domestic car manufacturers to provide recall repair information from the car rental companies because of "incidents involving allegations of personal injury and death" allegedly caused by "safety defects" on rental vehicles.
The best overall performance came from Enterprise. In a study of 10 General Motors and Chrysler recalls between 2006 and 2010, after 90 days, Enterprise had fixed an average of 65 percent of the cars subject to the recall.
For Avis/Budget, 53 percent of the cars were fixed . At Hertz, only 34 percent of the cars rented 90 days after a recall had been fixed.
The NHTSA study came after ABC News reported on "Good Morning America" last July on the deaths of the Houck sisters of California, 24-year old Raechel and 20-year old Jacquie, who were killed in an accident involving their Enterprise rental car. The car they were driving was a Chrysler PT Cruiser, one that a month earlier had been recalled because a possible leak in the power steering fluid could "result in an under hood fire."
The Houck's car was never fixed. Raechel and Jacquie died instantly after the PT Cruiser caught fire and hit an oncoming semi-tractor trailer on Highway 101 in Northern California. The sisters had rented the car in Santa Cruz, Calif., to visit their parents in Ventura County.
"We found out that they had rented this same car three times in that month period before they rented it to Raechel and Jacquie," Houck's family lawyer, Larry Grassini, said.
The Houcks sued Enterprise, and after a lengthy legal fight, the company admitted negligence and was required to pay $15 million in damages to the family. Now, the girls' mother Cally Houck is pushing the California legislature to pass a law requiring rental car companies to ground all recalled vehicles until they are fixed. Citing the Houck case, the Center for Auto Safety has also petitioned the Federal Trade Commission to require Enterprise to fix vehicles under recall before renting them out.
"I do not want another family to have to go through this type of ordeal," Cally Houck said.
Rental Companies Dispute Survey Findings
The rental companies dispute the survey findings, saying they pick and choose which recalls are most important, and have a high rate of fix for the most serious problems. Both Avis and Enterprise noted that after a 2010 recall of Pontiac vehicles over sticking accelerator pedals, they grounded and repaired the vehicles in question before renting them out.
However, the NHTSA survey found that in the 2007 recall of a series of Chrysler vehicles with a brake problem "that could cause a crash without warning," Enterprise/National fixed 65 percent within 90 days, according to the survey, and Avis/Budget fixed 61 percent. Hertz fixed only 46 percent within 90 days.
"They cannot pick and choose," Ditlow said. "They're gambling with your life."
Hertz said it has dramatically changed its policy and told ABC News that as of last summer, it now grounds all cars recalled for any reason, and will not rent them until they are fixed -- a change of policy that grew out of the public attention drawn to the tragic case of the two sisters.
Enterprise also said the government's recall figures are historical and do not reflect their performance in the most recent recalls in which they said repairs were virtually 100 percent complete within 90 days.
It is a position safety advocates said they hope the other rental car companies will follow. In the meantime, Ditlow said the best recourse for consumers is to simply ask rental car agents if their vehicle is subject to an outstanding safety recall.
"If they don't tell you, they're deceiving you and if they won't tell you, just go to another company, go to another counter," said Ditlow. "They're all right there in the airport, this is a free market, pick somebody who's more responsible."
Editor's Note - Correction:
An earlier version of this story incorrectly stated Enterprise had repaired 30 percent of the recalled cars. The correct number is 65 percent. The number previously reported for Avis, (26 percent) was actually 53 percent. The number previously reported for Hertz (21 percent) was actually 34 percent. The originally reported percentages for the brake re-call were also incorrect.
The misinterpretation was the result of the different ways in which the auto manufacturers reported their results. It was brought to ABC's attention by Enterprise.