Chinese-owned car maker Volvo Car (VOLVB.STO) recorded a 6% year-on-year decline in 2012 sales and expects 2013 to be “a challenging year in terms of margins and growth,” The Wall Street Journal reported. The company, acquired by Zhejiang Geely Group (0175.HKG) in 2010, said its sales dropped from 449,255 vehicles in 2011 to 421,951 last year as it phased out old models and combatted weaker consumer demand. Sales in the US, its biggest market, inched up 1% annually to 68,079 vehicles. Sales in China, its key growth market, decreased 11% year-on-year to 41,989 cars in 2012 and fell 24% year-on-year in December. The company expects 2013 to be “one of the most intense years in the company’s history.” It will be renewing its models, opening a new plant in Chengdu and pushing ahead with a US$11 billion five-year program to overhaul its vehicle platform and engine family.