I have a load of mp3 music files on my mobile android phone and I have the choice of connecting to my car's Kenwood head unit by either aux cable from phones headphone socket or by bluetooth. However, sometimes the Bluetooth connection plays up so I resort to the aux cable which is fine.. but if my phone is on charge there is a load of electrical interference noise?? Would it be possible to fit some kind of suppressor to the cigarette lighter to prevent this?