multiple gaming systems

Ok, so heres the idea, I want to setup my truck (2006 Colorado Crew Cab) for running 2 Xbox 360's, so that in a worst case scenario with 4 people playing the screen would only need to be split once. My question is: How would I hook it up so that if both units were operational at the same time (playing over system link), the sound for both would be audible through the car speakers, either half in the rear half up front, or half right half left depending how the video signal is set up. Deck I have is a DNX7100.

I would say if your auxiliary input is two RCAs, connect the white rca of each xboxs output to one channel RCA for the aux input. that will divide them left and right.

you trippin...2 xbox 360s??...damn you must got $$$$$$$ !!!!!!

any reason why the white and not the red?