If the car in front goes threw a red light, and theres a car next to you, a 2 lane road, sound the horn for a long blast and look at the driver next to you, with a shocked face, the driver who went through the light will think its him or her and not you if he looks in his rear view mirror.
Or on a dark night, just flash your lights once, the driver will think he has been flashed by a traffic light camera.
AWESOME work there project.
The guide books for Madrid used to advise British tourists to NOT STOP as the lights change to red because the two/three cars behind WILL expect to be able to go through. Therefore if YOU stop on the red YOU would be seen as the cause of the accident.
That said the trick when waiting for light to change to green was to watch the lights of the other traffic flow, when they changed to red then irrespective of your light still being red, you could be confident that green was coming and therefore launch yourself...
It has tightened up a bit recently.