INFINITI today reported sales of 12,514 vehicles in the U.S., an increase of 15.6 percent for its best May ever and an increase of 24 percent for the year. The Q50 sports sedan was up 42 percent. Sales of the all-new Q60 sports coupe (photo) increased 844 percent to 972 vehicles. Overall, INFINITI coupes and sedans were up 61 percent for the month.