Volkswagen ranked fifth with sales soaring 85.5 percent annually and 7.3 percent month-on-month to 1,627 units.

Mercedes-Benz ranked third with sales of 2,378 units last month, up 43 percent year-on-year and 10.6 percent month-on-month, while Tesla Inc grabbed the fourth spot with sales of 2,296 units, a 2.83 percent increase from a year earlier and 10.2 percent from May.

Lexus was second with 3,003 units sold, making it the best-selling luxury vehicle brand for five months in a row, Hotai said. Toyota was the top imported vehicle brand last month, with 3,090 new units registered, and its Corolla Cross was the best-selling imported model at 2,481 units, Hotai said. Imported vehicles made up 53 percent of total sales last month - the highest level in more than three years - as consumers bought 22,433 units, 54.8 percent more than a year earlier and a 6.7 percent gain from the previous month. That growth momentum is expected to extend into this month, with total sales estimated to increase 15 percent year-on-year, or 3.82 percent month-on-month, to 44,000 units, Hotai said.

Global city auto sales inc