BYD Co., a Chinese automaker backed by Warren Buffett's Berkshire Hathaway Inc., said its cars are poised to begin hitting U.S. showrooms by next year, Bloomberg reported. Des Moines-based MidAmerican Energy Holdings Co., a Berkshire Hathaway unit, in 2009 acquired a 9.9 percent stake in the company, which produces electric cars. BYD is returning its sights to the United States after billionaire founder and Chairman Wang Chuanfu completed a three-year reorganization in 2013, during which he cut the number of dealerships and narrowed losses at its solar business thanks to state incentives. BYD plans to introduce about four models for its U.S. debut at the end of 2015, said Stella Li, the senior vice president in charge of the company's U.S. business, in an interview last week in Shenzhen, China.