General Motors dropped nearly 3% in premarket trading after the autonomous-driving leader's departure announced.The chief executive of Cruise, the autonomous-driving-focused segment owned by General Motors Co. , is leaving the company, the carmaker said Thursday afternoon. Dan Ammann, who came on as CEO of Cruise in 2019, will be replaced on an interim basis by Cruise's president and chief technology officer, Kyle Vogt, according to an announcement issued by GM on Thursday afternoon. Wesley Bush, the former chief executive of Northrup Grumman Corp. and a GM board member, was also named to the Cruise board on Thursday.