I just typed up a long-exasperated answer to a question you didn't ask. I realized after looking at the subs you chose that the enclosure comes with an amp. That's a good start, you may have luck taking the line level signal from a rear speaking into it, you may not. I did not have luck with my system and instead had to take the subwoofer (bose system in the si) and feed into a LOC then feed back into the amplifier. If you look to the left on the connections, that's where the wiretap is going to go into, it shows L+ and L-, same with R, which means it wants the left signal and also a right signal, since you are pulling after the signal is amplified you'll put the input level to high (low level is preamp signal, this is available at the back of aftermarket head units normally). You will also want to get a remote bass knob. This is just because of how our head units control the signal, you'll specifically want to turn the bass setting down in the menu so that bass doesn't feed through the corner speakers, this would drown out the mids, then use the bass knob to fine tune the pure bass from the sub. The alternative route, some connoisseurs like doing it this way and say it's the best way, is to get a line output converter. Essentially feeding line level input into an amp like that will work, but the factory head unit has bass roll off at a certain frequency, as to protect your speakers. It doesn't want to feed a signal that will hardly work or cause wear and tear on an 8-inch speaker, and the 12 inch one you are putting into the car can easily handle that. Thus, people say the roll off can negatively affect how the subwoofer operates, a line output converter restores this roll off.
That's about it for my second long-exasperated answer. Let me know if you have any follow up questions, I had to do quite a bit of extra research before doing my system (Working on fiber glassing a custom sealed enclosure for it in the rear corner of the trunk next)
