If you turn your A/C on it should do it continuously like clock work. Try it at idle and it will do it and you can time it. Its much more often then you thank. My wife drives our car, and I too am afraid someone will think that she is flashing them. I have contacted Congressman Duncan in Tennessee and Attorney General as this is a safety issue. This is distracting to you and others around you. Your tail and brake lights are also diming or blinking. Keep in contact I am going to fight this.