Toyota Motor Corp. seems poised to overtake General Motors Corp. as the world’s biggest automaker, but lately the Japanese auto giant is finding the road to the top awfully bumpy, the Los Angeles Times reports.

A handful of top Toyota executives have made high-profile exits to rival manufacturers. Environmentalists complain that even as the company says it will sell 250,000 hybrid autos this year, it’s still producing gas guzzlers like the Sequoia SUV and moving to oppose more stringent fuel and emission standards. And perhaps most critically, it’s been beset with bad news on the quality front.

After announcing a record number of recalls in the last three years and witnessing its J.D. Power & Associates quality rankings slip significantly, Toyota was demoted by Consumers Union, publisher of Consumer Reports, on its annual reliability rankings. This month the automaker was hit with a lawsuit accusing it of covering up manufacturing defects at a California plant it shares with GM.

Critics say it’s proof that Toyota is growing too much too quickly. But Toyota brass, used to glowing public receptions, say it’s just a reminder that when you’re on your way to being the top dog, everybody wants to bring you down.

“It’s very puzzling,” Toyota spokesman Bill Kwong said of the quality criticisms, rattling off a long list of indicators showing that in many cases Toyota reliability is still very high. He added that Toyota President Katsuaki Watanabe recently appointed two executives to oversee quality control, announced plans to hire 8,000 more engineers to work on that issue and decided to make more prototypes of cars prior to release. “We’re very concerned about quality,” Kwong said.

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