At GM's expansive technical center, 30 miles south of Orion, engineers worked to make the Sonic accelerate faster and ride quieter than the Aveo, its cheap South Korea-built predecessor. The Sonic emerged with hatchback and four-door versions. It came in eight colors, including bright orange, and it got up to 40 mpg on the highway.

The car hit showrooms with a sticker price of just under $14,000 â¿¿ $1,300 less than the Fit. A year later, the tiny Chevy was the best-selling subcompact in the country. Last year, GM sold more than 81,000 Sonics. Hyundai's Accent finished second at 61,000.

GM is confident the Sonic will soon turn a profit, largely because workers at Orion keep finding ways to cut costs. Earlier this year, a team in the body shop suggested a small fix in the plant's machinery. It ensures that the car's frame fits together correctly every time and reduces the amount of steel going to the scrap heap, saving money.

"We recognize that we've got to work together as partners, because we're going to succeed or fail together," Orion Plant Manager Steve Brock said.

Even the wage differences don't seem to be a big source of friction. Tammy Ballard, who makes the lower wage that is now $16.66 per hour, said workers don't ask each other about pay. She left an auto-parts company for greater job security at GM.

"I knew what I was coming into, and I'm satisfied with that," she said.

On her purple T-shirt is Orion's slogan: "We build it like we own it."

Two months after the plant reopened, Obama and South Korean President Lee Myung-bak visited to celebrate a new free trade agreement. It was a little over 27 years since President Ronald Reagan had spoken at the plant's dedication. Obama trumpeted his familiar campaign theme about saving thousands of jobs.

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