The answer to the crossword is UNSER. Al Unser is a legendary American race car driver who won four Indianapolis 500 races, in 1970, 1971, 1978, and 1987. He is the only driver to have won the Indy 500 four times, and he is also the first driver to win the race three times consecutively. Unser is also a two-time winner of the International Race of Champions, and he was inducted into the Motorsports Hall of Fame of America in 1990.