Chinese automaker BYD is offering free repairs of the air-conditioning evaporator for owners of its Dolphin hatchback after hundreds of complaints that the systems were emitting a white powder. A group of nearly 400 BYD owners affected by the problem has raised the issue with local regulators, according to a document published by the Wenzhou Consumer Council, a local industry body that handles consumer complaints, on Wednesday. BYD sent out a letter detailing the voluntary repair program on Friday, adding that the powder contained no harmful substances and was actually aluminum hydroxide, an element often used to treat symptoms of increased stomach acid. [Jiemian, in Chinese]