Weeks after voters dissed the Democrats, an important economic benchmark was passed with little public notice: The U.S. government sold off its stake in Ally Financial, the auto financing company once known as GMAC. It even made money on the deal -- about $2.4 billion.That sale ended the six-year effort to rescue the American auto industry from financial disaster. Treasury Secretary Jacob Lew was correct in saying, "This program worked."In 2014, American carmakers sold 16.5 million vehicles, their best year in almost a decade. That boom fits into a broader picture of economic progress: declining unemployment, soaring stock prices, steady inflation and interest rates.