who can tell me some informationg about cts dvd system

hello everyone ! i am from shanghai china . i have a 05CTS china version . my CTS equipped a U57 nav dvd system .i am game fan .i heard additional video signal can directly input the nav dvd system in some type sedan .wether my nav system can support it? my meaning is i want to use two wire connecting my nav system's back side ,but i don't know more information on it .
who have do it ,
who can give me some advise !
thank you everyone! appreciate from china!

Hi,
Just open up the console cover and plug in the RCA jacks right in the back.

Good Luck