I actually own two of those
SW, and have a Focal 6.5" component set. I have never used the SW's. They are brand new in the box. I just never got around to figuring out what to do with them. They are a tricky bit to put in. First, the door is not a good option. These subs require an enclosure, and there is typically not room in the door with all the window mechanisms. Second, the components belong in the kick panels, so that space is taken. That generally leaves a cavity in the dash, center console, or maby under the seats for placement.
Bear in mind that these just produce the low end. They are not going to hit in anyway. Of course, if you have heard a car tuned for IASCA competition, you know what I mean.