Complex sentence: His doctors succeeded in banning him from the 1955 Redex trial, though he did later take part in the Ampol round-Australia reliability trial in 1956, again driving a Ford Customline, and the 1957 and 1958 Ampol trials, driving Chryslers.
Split into simpler sentences: His doctors succeeded in banning him from the 1955 Redex trial. Though he did take part in the Ampol round-Australia reliability trial in 1956, again driving a Ford Customline, and the 1957 and 1958 Ampol trials, driving Chryslers.