Teensy dots
Totally random and stupid thought.
Why did car stylists
hate lights for so many years? They did everything possible to eliminate taillights entirely, and often tried to hide headlights behind tricky and troublesome hatches. Before 1950 the typical taillight was about one inch in diameter. Coming up on a car at night, you couldn't tell distance or width until you were too close to need lights.
This tendency was international. US, British, German, Italian cars all had teensy dots for taillights until the '50s. It couldn't be a matter of cost; the wiring and installation were the same, and the materials might have been different by a penny or two. Installing a 6" item is easier and faster than installing a 1" item, so the labor time would compensate for the pennies.
Now taillights are BIG. Maybe too big in some cases, but that's a much better deviation from midline.
Same goes for signal lights of all sorts. Directional signals came late and didn't become standard until the early '60s. Modern cars have directional indicators all over the place. Front, back, mirrors, side. Again maybe a tad too much, again it's better to err on the side of MORE visibility.