Video Advice

Tried to get this info on the Cadillac Owners Group Forum with no luck. Let's see if one of you guys can nail this.
I want to feed the video signal from my nav screen to another monitor/s.
So the other monitors (headrests) will display all info, nav, bluetooth, DVD, radio functions, etc.
My car is an 05 STS4 1SG........................

Thanks very much.................... Joe P