Wuthikorn Suriyachanthananond, vice president of the company, said sales of passenger cars dropped 21.1 per cent to 23,139 units last month, while sales of commercial vehicles were down by 16.2 per cent to 33,803 units. This includes 1-tonne pickup trucks, whose sales declined by 21.6 per cent to 25,850 units from the same month in 2014.