38th President: Gerald Ford, 1974 

Movie = 38 (Ford was the 38th president)

Ford (cars) = Ford

Biker = 974 = 1974 became president

Jerry (cans) = Gerald

All the people watching the movie (38) at the drive-in cinema drove Ford (Ford) cars, which was strange seeing as the film was about a biker (974=1974). 

Connect Ford to Gerald

On the back of all the Ford (Ford) cars were strapped Jerry (Gerald) cans because it was such a long way to the movies.

NOTE: The way Mammoth Memory remembers Gerald is to think Gerald the Jerry can.