The Betsy (1978)

The patriarch of a family-owned corporation hires a young race car driver to help him design a fuel efficient car in secrecy. They face resistance from the president of the company (the patriarch's grandson), who wishes to eliminate the motor car division because of bad blood between himself and his grandfather. During flashbacks, a parallel set of problems is revealed in the family's past, problems that persist into the present, and the race car driver gets deeper into the web of deception and corporate intrigue.