[Nicaragüense]

As far as the hiss goes, that might be interference from the grounding in the vehicle since it only happens when you connect it to the charger. The problem about the phone taking over and drowning out the radio stations while plugged in though is beyond me. Are either of those vehicle equipped with Windshield antennas? Aftermarket or original sound system? try the phone in a third vehicle to see if it is definately a consistent problem..