Not at all mustang related,but didnt know where else to go. My wife has a 93 Camry. A couple of years ago, her dad rigged up an pioneer headunit to her stock speakers. Recently, it has begun to make a popping sound through the rear speakers when ever the car is running. it sounds a lot like radio static. This is with or without the radio/CD player on. I know it is not wired correctly, because he supposely used the wire to the cig lighter for power.