The Trump administration announced it would investigate possible tariffs on auto imports on national security grounds. But, how exactly is the auto industry connected to national security? We sent Marketplace's Sabri Ben-Achour on a hunt for answers. And while we're on the subject, we talked to a sales manager at a German auto parts company with a U.S. factory about what the Trump administration’s investigation into possible auto import tariffs could mean for his business. Also on today's show: The story of one scientist’s search for a new red pigment that could be worth a billion dollars.