
1) Al at Indy 2) Al behind the wheel 3) Al of auto racing 4) Al of indy 5) Al of Indy fame 6) Al of NASCAR 7) Al or Bobby of auto racing 8) Al or Bobby of racing 9) Al or Bobby of racing fame 10) Al who won four Indy 500s 11) Al, Bobby or Al Jr 12) Andretti adversary 13) Any of three Indy winners 14) Auto racer al
Found on
https://www.crosswordclues.com/clue/unser

(Al), born 1939, and his brother(Bobby), born 1934, U.S. racing-car drivers.
Found on
https://www.infoplease.com/dictionary/unser
No exact match found.