Satisfaction
Artist's commentary
Hang in There, Kogasa-san 3310
It feels like the margin of error was ±20 meters.
The numbers change heartily when accelerating or decelerating, which is fun. They gradually come back, though. They also change when light shines on it.
That final dot on the display indicates motion detection in progress, by the way. It disappears when the car is stopped. I'd initially intended it to turn on a separate LED, but I figured this was good too. :-)