The only feature length film I was in I was one of a "couple" of hundred extras. It was in the mid 70's, with some falling "stars" like Artie Johnson & I can't remember who else, that did some movie about a car-aka horseless carriage. They filmed some scenes out in a wildlife refuge near Lawton, Oklahoma & invited people with period costumes to show up. Because I was in & had made a costume for a production of Oklahoma, the director of that production let me & everyone else know that extras were needed for the film. As I recall, we got $20 per day-for 2-3 days, & signed some papers that no one read including me. (I think I was about 20 or 21 & never read anything I signed back then)   I don't think any of our faces were recognizable on film. I only saw some of the daylies, and had moved before it was shown at a theatre in Lawton--and not too many other theatres in the world.
The name of the film was something other than we were told. It was a box office flop. I don't know if it was even on tv. Pathetic, huh?