We are fortunate than many of the car companies in the fifties and sixties had very competent pr and publicity departments, films of rallying and Le mans are widely available, Rootes, Ford, BMC, Standard Triumph to name but a few, frequently featuring Biggles Baxter on commentary.
The other excellent period films are from the John Tate collection, he was a Tate and Lyle Tate, so 16 mm film equipment gave excellent results, he ran an Aston road car so as well as the large international meetings he filmed at VSCC and Aston clubbies, well worth digging out.