Gus is a 1976 American film by Walt Disney Productions about a football-kicking mule ("Gus") and his trainer "Andy" (Gary Grimes) (Wikipedia).
This film surprisingly had many notable actors and two legendary NFL stars including Don Knotts (former resident of Glendale), Edward Asner (resident of Studio City), Dick Van Patten, Harold Gould (passed away in Woodland Hills), Tom Bosley, Liam Dunn (passed away in Granada Hills), Bob Crane (formerly interned at Chatsworth's Oakwood Memorial Park), Ronnie Schell, Dick Butkus (NFL Hall of Famer with the Chicago Bears), and Johnny Unitas (NFL Hall of Famer with the Baltimore Colts and arguably one of the greatest NFL players).
You can view more SFV Filming Locations here.
I am not 100% sure but I think the opening scenes of the ranch that were used throughout the film were at Disney's Golden Oak Ranch at 19802 Placerita Canyon Road Newhall CA.
The practice scenes at the football stadium was actually CSUN's football stadium at the former Devonshire Downs Fairgrounds at 18000 Devonshire St Northridge. This location has now been converted to a Medtronic plant. Prior to Medtronic, this historic site was a horse racetrack, concert venue, fairgrounds, and, motorcycle racetrack. You can learn more here. Additionally, CSUN plans to convert the site they own into affordable housing for students and staff. This location was also used in the 1979 film starring Steve Martin, The Jerk.
|In this scene, you can see the old CSUN dorms that were demolished after the earthquake on Lassen.|
|In the background, you can see the apartment complex located at 17951 Devonshire Street.|
The drive-in theatre location I am not 100% sure but I believe it was the Pickwick Drive-In formerly located at 1100 W. Alameda Avenue Burbank. You can read more about SFV Drive-In's here.
|I never knew this before but popular James Bond villain, Jaws, played by Richard Kiel appeared in this movie.|
VA Sepulveda Ambulatory Care Center 16111 Plummer St., North Hills, CA 91343. At the entrance to the hospital on Plummer was also used in this film shown below. This location has been used in countless movies and was also used for the 2012 Best Picture, Argo, discussed on this site.
I am not familiar with the location where Gus is at a Chrysler Used Car lot but possibly in Van Nuys, Reseda, or Canoga Park.
The scenes at the Ralphs Supermarket was located at 12921 Magnolia Blvd Sherman Oaks 91423. In the movie, they state that Gus was spotted on "Topanga Canyon" but unfortunately they didnt actually use any actual scenes from "Topanga Canyon."
And the movie trailer: