I have a 2007 DTS that will (seems when it is cooler) have a loud popping sound when first started. Sounds like someone is slapping the windshield and it scares the heck out of you. Been to dealer twice and they have replaced radio amplifier. I guess the noise is actually coming out of the front speakers. After twice now, still not fixed and still getting a popping sound. Has anyone else had this and if so what was the fix. My wife does not want to drive this car as she fear it will start on fire since there is an apparent electrical short. Thanks in advance!!