Yeah Ive installed the kicker sub I bought from a friend. Found a .pdf file on this site:
Kicker Installation Files
I think its the Kick01 file.
Basically if you get a new one from the dealer theres no worries cause its got a wiring harness and instructions.
If you bought if from a friend you'll have to splice into the rear speaker wires and run a power wire to the head unit. A metal terminal is inserted into the factory stereo's wire harness. Not sure where you could buy the terminal, I had an old wireing harness lying around and yanked one out of that. I grounded the amp as it was shown in the directions.
The sub sounds ok. Gotta have the back seat down to really hear it though.