Can anyone give me the specs required for a good sounding bass box for 12" subs. Preferably dimensions, diagrams, suppliers, anything so that I can get some decent sound from the boot on my Mk V cabbie? Please help!!

as title really.

Planning on getting some 4" infinity speakers for the front and rear of my mk4 cab, just wondering what kind of speaker connection is already there, is it the dodgy ford connecters or just standard red and black cable tied around a bit of metal on the speakers? Can you get adapters if it is the Ford type?