I have a come up with a list of license plates from movies and TV shows. They all show prominently in the frame for enough time to be read easily. The solution to the "puzzle" is just a list of the shows and movies they come from.
I wonder if this is appropriate for the site, as it's not something you can deduce from logic or clues; it's just something you might have by your side while watching stuff and you might find some of them.