At the beginning, just after the title credit the President's car is machine gunned and you see the back windshield shatter and disintegrate. Moments later the car arrives at the airport with the windshield intact. We see de Gaulle get out of the car with the intact rear windscreen.
Fred Zinnemann wanted the Jackal to be played by an anonymous actor, so he passed over established stars such as Michael Caine, Roger Moore, and Jack Nicholson in favor of Edward Fox. He later admitted that his decision might have been what contributed to the film's sub-par performance at the box office.