Ok, I just replaced my sub with the $13 dollar pyramid speaker mentioned above. I went with this method as I do not like to cut and splice my factory wires. I am just excessive compulsive LOL. It works pretty good. Sound at least as good as the stock sub from what I remember, probably better. Remember that you will have to grind a little of the plastic (straight down in the opening) kind of where the magnet would sit from the pyramid sub. I used a dremmel to grind it down. It is the half moon looking ledge in the bottom of the box. Now as far as the wiring goes, on the 04 in which I have you will use the red and black wire ( I used red to positive and black to neg.) I taped the gray and brown up reall good and used some small wire ties to fasten those wires neatly to the other speaker wire harness. I didn't even have to cut the factory connectors on the red & black wire. One wire fit on the the pyramid sub fine, and the other I pinched a little with some needle nose pliers. For $13 and about 30 minutes time, you can't go wrong with this little speaker. As far as wiring I think the speaker colors are different below 2004 year. But I am pretty sure that with 04-06 you will use the red and black. The best thing to do, if not sure, is sit inthe Jeep with the factory sub box, and hook up the two wires at a time until you get sound. As far as screwing the speaker in, line up the speaker how you want it. I used some small self tapping screws (easier than factory ones) I used a very small screw driver and heated the tip up real hot and pused it right through the plastic to get my holes. Then I VERY CAREFULLY screwed the speaker in. Be careful not to slip with the screwdriver and blast a frigging hole in the new sub. Last, before you put the console back in the Jeep, don't for get the screws that hold the sub box to the console (on the outside) because it is very difficult to get to them with the seat in the way. LOL Good luck, I hope this helps.
Take care
Mike