Posted this in under the hood too, then saw this sub section. Mods if you are reading please feel free to delete other thread.

Hi Guys,

Got stuck in some bad traffic the other day and decided to get my GPS out to find an alternative route. Plugged in the charger into my cigarette lighter and the stereo went straight off. As soon as I take the charger out the stereo comes back on, very annoying knowing where you are going but with no music or not knowing where you are going but have music. Has anyone had this problem and does anyone know how to sort it out? Thanks in advance.

Edited to add - I also have another problem where my aftermarket stereo a sony MET-BT3900U keeps going into demo mode, not when I turn it on but when I'm driving it will randomly start listing all of the features on the screen like it would in the shop display. There is no loss of audio when it does this but it is doing it quite often and while I can press the display button to get it back to the radio screen it is becoming a bit annoying. Any ideas?