When I was a sweet, innocent child, I thought every car should have a scrolling LED display in the rear window to say “Fuck off” to the guy who’s driving too close to your bumper (did I mention how sweet and innocent I was?). Then I decided technology afforded us better alternatives, and we should have a wireless communication system that would allow you to broadcast spoken messages to a nearby car by selecting it with a wheel-mounted joystick. Then I realized that the surest way to turn the city roads into a reenactment of Mad Max was to enable communication of any sort between cars, so we were better off sticking to blinkers and brake lights.