You're driving down the road, calmed by the soothing sounds from your favorite Christian radio station when, all of a sudden, Howard Stern hijacks your radio. This is just the most outrageous example of a phenomenon radio station managers in the lower end of the FM spectrum have been hearing from listeners in recent months, a situation they attribute to improperly installed satellite radios. The improperly installed radios turn automobiles into powerful mobile transmitters. The interference temporarily blots out specific radio frequencies of nearby automobiles and homes, replacing it with the passing automobile's satellite radio broadcast, which can include Stern's...