The stranger memorizing the license plate from a single announcement on the radio and then finding that car on the street to deliver news of a sick kid is a fantastic story.
It's hard to imagine for someone brought up in the age of the information overload just how starved people were back then for entertainment and news. I remember the anxiety with which I waited a whole week for my favorite (and only) cartoon I could watch on the national television (the only TV station available). It was a Japanese show called Spaceship Sagittarius and the episodes are forever burned into my memory down to the planet names the protagonists were visiting, minor characters and plot twists. Back in the 50s, I could imagine thousands of people memorizing a license plate announced on the radio, and the story of the SOSes becoming talking subjects in the local pub.