The new employees will be part of a larger, busier workforce. From coast to coast, the industry is in top gear. Factories are operating at about 95 percent of capacity, and many are already running three shifts. As a result, some auto and parts companies are doing something they've been reluctant to consider since the recession: Adding floor space and spending millions of dollars on new equipment.

"We're really bumping up against the edge," says Michael Robinet, managing director of IHS Automotive, which forecasts auto production. "So it really is brick-and-mortar time."

The auto industry's stepped-up hiring will help sustain the nation's job growth and help fuel consumer spending. On Friday, the government said U.S. employers added 175,000 jobs in May, roughly the monthly average for the past year and a sign of the economy's resilience.