Original sentence: (1) Al Unser succeeded Ongais as driver in the car;  Unser won the Indianapolis 500 with a March-Cosworth that had been a show car.(2) After Scott Brayton was killed in a practice crash with a backup car, Ongais drove the car Brayton qualified on the pole;  under USAC rules, the car had to start last
Edited sentence: (1) Al Unser succeeded Ongais as driver in the car; Unser won the Indianapolis 500 with a March-Cosworth that had been a show car.(2) After Scott Brayton was killed in a practice crash with a backup car, Ongais drove the car Brayton qualified on the pole; under USAC rules, the car had to start last