Vietnamese electric vehicle manufacturer VinFast(VFSpongarcade.US) fell 15pongarcade.5%pongarcade, quoted at $5.34. on the news frontpongarcadeThe U.S. National Highway Traffic Safety Administration (NHTSA) said on Monday that it has launched a formal investigation into a crash in April involving a VF8 SUV made by Vietnamese electric vehicle maker VinFast that killed a family of four.