2007 Prius is experiencing an intermittent very loud static noise coming from all speakers. It is so loud that it sounded like a train crash three feet away. The loud static will continue even after the radio is turned off. The static seems to occur after driving 1-3 hours. The car is a single owner and has never been in an accident. There is 67,000 miles on the car. There have not been any aftermarket additions. Once the static starts, the only way to stop it is to pull the radio fuse from under the hood.
The Prius has the JBL system with the Amp under the RF seat. I attempted to go to the Toyota dealer (Wiesbaden, Germany) and they could not duplicate the problem and suggested they keep the car and send off the head unit and it would take 4-6 weeks (I can't give up my wife's car for that long). I also attempted to have an aftermarket audio installer to check for shorts (he wouldn't touch a factory installed system to troubleshoot???) I miss being back in the States.
Can you offer a suggestion on cause and correction of intermittent loud static noise coming from all speakers.