For United Auto Workers union members Jermaine and Akema Austin, a two-tier wage system at General Motors Co (GM.N) is not just business, it’s personal. GM has two classes of UAW workers – long-time “first-tier” employees, who earn about $28 an hour, and “second-tier” workers hired after 2007, who earn about $16 to $19 an hour. Detroit automakers, which pushed for and won the two-tier system in negotiations with the union, say the freedom to hire workers at lower wages has helped them recover from near-death in the recession and add thousands of U.S. jobs in recent years.