I have had my new car 3 weeks now and have noticed a back ground noise (hiss / interferance) when the radio / ipod is on. Tonight I have now found that I get the same noise from speakers when the car is unlocked and the door is opened. Is this usual ? Anyone else get the same noise ? Unit is a Audi RNS-E with Bose speakers and ipod adaptor. Any help or advise I would be greatful. There is already a fault that the DVD will not eject !