I finally figured out which movie I was thinking of. It was a movie I watched maybe 20-30 years ago.
There is an old World War II movie where two British POWs are trying to escape the Germans. What made the movie memorable for me was its final scene, where they steal a fire truck from a bombed-out abandoned fire station and on their way to the American lines, they encounter a convoy of German soldiers. Instead of panicking, they put on the fire fighter's helmets, start ringing the bell, and the German convoy pulls over to let them pass.
It's an old black and white movie from 1962 called The Password is Courage.
https://en.wikipedia.org/wiki/The_Password_Is_CourageThe movie was made before I was born, but this goes to show you, a good story is a good story.
