Jack Gillis, executive director of the Certified Automotive Parts Association, said his group supports the certification model "because no one in this room can look at an aftermarket part and make an informed judgment as to its quality or performance."

Mr. Gillis said independently produced aftermarket parts will provide consumer choice while maintaining safety standards.

But representatives of the auto industry said that such independently produced parts cannot provide the quality and safety required.

"It is unlikely that an impartial certification entity can be created and relied upon to serve consumer needs without unduly focusing on the bottom line, the result of which may be an inferior crash part," said James Moors, director of franchising and state law for the National Automobile Dealers Association, in a letter to NCOIL President Rep. Craig Eiland.

David Snyder, vice president of the American Insurance Association, said the NCOIL model would actually reduce competition by removing the option for a collision repairer to use parts guaranteed for life by the insurer.

He said that current laws in states "encourage competition in parts, repair and provide minimum standards and notices."

The lawmakers will consider an amended model at their annual meeting in November.