Before Can Am the sports car racing series was known as the SCCA (Sports Car Club of America ).
In late 1964 the racing was getting competitive with the Chaparral starting to win races and Bruce McLaren was showing his skills in the first of his sports cars.
At one of the last races at Monterey (Laguna Seca )the Chaparral driven by Roger Penske (filling in for an injured Jim Hall) won the races and for most of the day, run in two heats, people saw only the Chaparral from the rear.
(Thanks to Car & Driver magazine. Jan 1965. for the photos )
(Ken Hyndman, still researching this subject.)