MEXICO CITY/SAO PAULO—Automotive production in Brazil and Mexico, Latin America’s two largest economies, plummeted in September, dragged down by an industry-wide semiconductor chip shortage and railroad blockades in Mexico, data showed on Wednesday. Brazilian auto production was down 21.3 percent to 173,287 units in September from the same month in 2020, when the industry was scrambling to resume production from a coronavirus-induced shutdown, Brazilian automakers association Anfavea said. In Mexico, auto output plunged 33.30 percent from September 2020 to 208,092 vehicles, while auto exports fell by 24.18 percent to 195,294 units, data from national statistics agency INEGI showed. “All of this is due to the shortage of semiconductors, which at this point is affecting all levels of production for all participants in the domestic market,” said the head of the Mexican Automotive Industry Association (AMIA), Fausto Cuevas. A semiconductor chip shortage is causing major auto production cuts around the globe …