Hindustan Motors, a C K Birla group company, today said sales of Ambassador increased 51.16% in December 2004 to 1,303 units as against 863 units sold in December 2003."The growth in sales of the Ambassador can be attributed to the continuous improvements we have been bringing in the product," Soni Shrivastav, general manager, corporate communications of the C K Birla group, said.Ambassador sales has been increasing since the beginning of the financial year. "The company recorded a 7.17% growth in Ambassador sales between April-December 2004 by selling 8,907 units as against 8,311 units sold in the corresponding period of the last fiscal," Shrivastav said.