WASHINGTON—Volkswagen’s U.S. unit has agreed to a $42 million settlement covering 1.35 million vehicles that were equipped with potentially dangerous Takata air bag inflators, according to documents filed in U.S. District Court in Miami. The settlement is the latest by major automakers and much of the funding goes to boosting recall completion rates. To date, seven other major automakers have agreed to settlements worth about $1.5 billion covering tens of millions of vehicles. Volkswagen did not immediately comment. The defect, which leads in rare instances to air bag inflators rupturing and sending dangerous metal fragments flying, prompted the largest automotive recall in history. To date, at least 19 U.S. deaths have been attributed to faulty Takata air bag inflators. Honda Motor Co. said in April it had confirmed the 19th U.S. death tied to a ruptured Takata air bag inflator since 2009 and the 16th in one of its vehicles. …