I am having an ongoing issue with the stereo system in my 2007 Caliber. Every so often there is static in the speakers. Most of the time it is the speaker in the passenger door that has the problem but the static has been noticed in other speakers as well. It does not matter what source is being used (radio, cd, satalite) the static remains for about 5 min and then disappears. All the speakers have been replaced as well as the stereo deck (twice) but the problem remains. Also there was a TSB related to insulation in the door panels which has been installed but again the problem is still there. The local dealership seem unwilling to rewire the system. Has anyone else experienced this issue or have a suggestion as to what may be causing this? Any help would be appreciated.

Sounds to me like it could be a grounding issue.