Unser dominated the race , but co-driver Ivan Bellarosa crashed the car out .
In 2013 , Unser entered a sportscar race at Thunderhill Raceway Park , the legendary 25 Hours of Thunderhill , racing with his son Al III as teammates .
Unser dominated the race , but co-driver Ivan Bellarosa crashed the car out .
In 2013 , Unser entered a sportscar race at Thunderhill Raceway Park , the legendary 25 Hours of Thunderhill , racing with his son Al III as teammates .