BYD Auto Co., Ltd. is a Chinese automobile manufacturer based in Shenzhen, Guangdong Province, and a wholly owned subsidiary of BYD Company. It was founded in 2003, following BYD Company's acquisition of Tsinchuan Automobile Company in 2002. Its principal activity is the design, development, manufacture and distribution of passenger cars and buses sold under the BYD brand. It also has a 50:50 joint venture with Daimler AG, Shenzhen BYD Daimler New Technology Co., Ltd., which develops and manufactures luxury electric cars sold under the Denza brand.