BlueMusic Humming

[PlasticMac]

On the Audi, there is a charge lead plugged in to the phone. i saw your comment about USB chargers earlier, and I will see if it happens when I remove the charge lead. And try that trick on the Rover
The Rover, the Amp is a 4 channel amp IIRC, will check when I get home. All the inputs are also used IIRC.

I was wondering how two line outs, from the radio, feed four inputs to the amp.
Mac.