blackpologti

First post! I've got a 920BT which I'm installing into my car. Just test fitted it today and aside from nightmares due to can-bus I noticed that the buttons were illuminated all the time, regardless of whether the lights were on or off. The unit itself seemed to be able to recognise whether the car lights were on of off though, as it changed the display of the 3D map screen. Can anyone confirm that this is correct or have I got a defective unit? Thanks