lexus rx300

i am trying to find the wire from the factory lcd monitor to the handbrake switch that stops the factory dvd system from being viewed unless the handbrakes are on. does anyone know where i can find this info.  this is not being done for the driver but for his kids that are driving him crazy in traffic. any information would be appreciated.

What you can do is go straight to the hand break wire and ground the wire there via a toggle switch. Kind of like an on / off switch for the monitor while driving. The only problem with this is that the hand break light will illuminate while the LCD monitor is on while your driving when the switch is ON . If you can handle that little light being on, then it is a much simpler way that having to try to find the ground wire going into the video system of the Lexus.