WASHINGTON (Reuters) -The National Highway Traffic Safety Administration (NHTSA) said Thursday it is investigating a March 3 fatal crash between a Ford Mustang Mach-E and two stationary cars in Philadelphia in which an advanced driver assistance system could have been in use. This is the second recent Ford crash under investigation by the auto safety regulator and the National Transportation Safety Board (NTSB) in which a driver assistance system is suspected of being in use. The March 3 crash i