EnergyWire: It's not hard to see how energy fits into Kevin Butt's business of assembling 2,000 cars a day. "When we make cars, we argue about pennies sometimes," he said. "Make it better, but don't spend the money." Butt is the regional environmental director at Toyota Motor Corp.'s assembly plant here, where time and precision are measured down to the final bolt. More than 7,000 full-time workers a day pass through Toyota's largest assembly plant outside of Japan, a sprawling 7.5-million-square-foot space...