[SpookyZalost]

so update, I've done a bit of research and this is going to be trickier than I first assumed but not impossible.

first things first.
my radio has a wire that's currently disconnected as my car does not have a wire to detect when it's backing up, that's fine actually because one of my experiments is to apply voltage to this wire to see if it triggers the composite input, right now there's no way to select it manually but if all goes well I'll have a switch to trigger it on and off manually... that actually works out ideally because I love manual toggle switches! 

normally this wire would activate when you shift into reverse... but see my GPS already has wireless backup camera support so I might as well use this for something else.

now the real question is... do I setup my composite switch in the extra space inside the console between the seats or do I mount it to the inside of the roof like a space ship/rv/boat/sub lol.