Installing speakers in a cargo van

[modlite]

I'm a little confused on how to put speakers into the back of my cargo van. I looked back there at the wiring and the only thing i could find was 2 little plugs with 2 prongs in each of them. Is this where you would wire speakers? Or is the cargo not wired at all so I have to run my own wires? I just need to know what I need to do exactly. Also how are most speakers mounted? Just screwed to the back panel going over the door? I have a 900 watt sub on its way and new speakers for the back.

[phr1$k37]

That sounds right to me ... been a while since I have pulled off my covers for the speakers.