That's exactly how I acquired mine and it was also in a kicker prefab box, or at least the box said kicker on it. I'm not 100% sure, honestly. But either way the tuning of the box was like 38-40 Hz for some crazy reason. I had some leftover MDF, so I made the port an L and extended it 11". It was a dual 4 ohm and wired to 8 ohm, so I wired it to 2 ohm and gave it 650 watts and it sounded WAY better. I should also add that the box was starting to come apart, so I put a bunch of 2" screws in it and resealed it with Tite Bond 2. The carpet was kinda wore out in the box and it was old, so I sold it for $120.
EDIT: even tho I mess with car audio all the time, I've never built a bandpass box of any kind. If someone is dead set on that (very rare), I send them up the street to a shop. I also don't personally enjoy box building. I'd say 70% of the time I use slot ported and 30% sealed.