A few weeks ago I heard a loud popping noise from one of my speakers. It lasted only a few seconds and went away. Today I heard the same loud popping noise. I turned the stereo off and still heard the loud and sharp popping noise. I turned the stereo on and the popping noise jumped across all the speakers (sounded like it was jumping around the car). Then, the stereo stopped working - no sound for SAT radio, phone or aux input. Then, after the car sat for a while it worked fine.

Any ideas?