I have a 03 G35 and when I'm driving usually on the highway the engine will cut out and then kick back in and the slip light and other lights flicker on and off. It doesn't always happen sometimes i can drive the car for a week or two and nothing happens. Other times I can be on the highway and the lights on the dash will flicker but nothing happens.

My mechanic and the ones at the dealership don't know whats causing it and say they won't know until the car acutally breaks down. Has this happened to anyone.