they can give some very good results and tend to be very punchy bass wise
i suggest looking into jbl`s offerings too
to wire them in you need a wireing kit (£20) and depending on the unit either a set of rca`s or a set of normal speaker cables. you basically wire it in as you would do an amp and then strap it down and off you go. iirc jo guest has one in her car

(dont ask me how i know- ok i know a few club owners in leeds) there is one you can get that looks like a NOS bottle too