I have a 2005 A3 Sportback fitted with the original Concert II radio. It has recently developed a fault with the radio where it loses the reception every few seconds. I have traced it as far as the aerial connector, which goes short circuit every few seconds, before returning to normal impedance. The strange thing is that this only happens when the engine is running. I'm guessing it's something to do with the slightly increased voltage from the battery when the alternator is charging. Has anyone else experienced this fault before, and does anyone know where the aerial amp(s) are located on this model so I can follow the fault through. Any help would be appreciated.