At this week’s biennial Tokyo Motor Show, Toyota Motor Corp.’s booth didn’t feature any cars its customers can buy. Instead, the company showcased a mobile service that gives you a health checkup, with the slogan: “The star of the Toyota booth isn’t a car—the stars are people.” There’s a good reason Toyota is shifting focus from individual cars: The global auto market is shrinking. World-wide sales fell in 2018, are expected to drop again this year, and Moody’s Investors Service projects another decline in 2020. …