A volkswagen automobile sits for sale on car lot in Carlsbad, CaliforniaWASHINGTON/DETROIT (Reuters) – Volkswagen AG faces penalties up to $18 billion after being accused of designing software for diesel cars that deceives regulators measuring toxic emissions, the U.S. Environmental Protection Agency said on Friday. “Put simply, these cars contained software that turns off emissions controls when driving normally and turns them on when the car is undergoing an emissions test,” Cynthia Giles, an enforcement officer at the EPA, told reporters in a teleconference. Volkswagen can face civil penalties of $37,500 for each vehicle not in compliance with federal clean air rules.