GM posted solid gains in pickup trucks and crossover SUVs—among its most profitable products—and posted record sales for the year in both categories. The U.S. auto industry in 2017 likely suffered its first annual sales decline since the financial crisis eight years ago, as demand finally ebbs after a remarkable multiyear growth spurt. Most big car makers on Wednesday morning said sales declined in December from a year earlier, concluding 2017 with a thud. Car companies and analysts expect U.S. sales to fall further this year, below the 17-million mark, which would be the first time since 2014 sales haven’t exceeded that level. Still, a strong economy could improve the industry’s prospects in 2018. Gains in wages and employment have historically boosted new-vehicle demand, for instance. Auto makers are also reporting record selling prices, a sign that low interest rates and low gasoline costs are factors that encourage buyers […]