In a state straining to hire enough workers to sustain an expanding and evolving auto industry, mirror maker Gentex Corp. has an even tougher challenge. Its West Michigan manufacturing base is one of the state's tightest job markets. Ottawa County, Mich., where Gentex operates, posted a 3.1 percent unemployment rate in June, the most recent month available. That environment is a big reason the Zeeland, Mich., supplier is looking for new ways to recruit and hire people — not just for its current needs, but to support growth in the years ahead. Its two big efforts now revolve around social media and community-based advertising. The company wants to do more than fill jobs in Zeeland — it wants to build a local reputation that will attract future workers, said Craig Piersma, Gentex director of marketing. He has hired a dedicated social media employee for the human resources department's recruiting efforts. "The primary source of new recruits is social media," Piersma told...