Palm Beach Post: Automakers say they won’t have to overhaul their technology or flood the U.S. with tiny cars buyers may not want under President Barack Obama’s standards for fuel economy and greenhouse-gas emissions. Even as they face more than $21 billion in annual costs to meet the new standards by 2016, General Motors Corp. and Ford Motor Co. will benefit from a single national system, rather than a patchwork of state rules, and an approach that allows them to tweak the fuel efficiency for each …