I have installed the MEX-BT3900u as per the installation instructions provided by SONY. (this was simple and successful) I have also tried all THREE wiring options to maintain power to the unt so as to preserve the settings etc. Each option has come to the same conclusion, that is when I remove the key form the ignition (and in this cars case open the door) the power supply is then terminated to the unit and once again I have to turn off the demo and set the clock etc every time I turn on the ignition.....anyone got any bright ideas.
The car in question is a Renault Megane 1.5DCi - it did have column controls with the manufacturer installed unit but I chose not to spend the extras on the interface as it is easy to control either with the dial/iPhone or the remote control.
Many thanks in advance for your help
