Loopey

Just got a 2.5i Hatchback w/ premium package (no sat/nav option).
I thought I had read somewhere that they are "pre wired" for subwoofers / amps, but I could be mistaken. I did not get the sub/amp option on the car as I plan to install my own. I'm just wondering if anyone knows where I should look if the car is actually "pre-wired". Also, does anyone know if the stock 6-disk radio has pre-amp outputs on it?

Thanks