Key TakeawaysMorgan Stanley downgraded the U.S. auto sector and several companies in it because of growing competition from China.General Motors and Ford had their ratings and price targets cut.Morgan Stanley noted that China now produces 9 million more cars than it buys. Shares of General Motors (GM) and Ford Motor (F) tumbled Wednesday as Morgan Stanley downgraded the stocks and the overall U.S. industry sector because of competition from China. Calling it the "China Butterfly Effect," the analysts wrote ...