they also have the 3 inch square subs. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif in all reality though, there are 6.5 inch subs that do pretty well actually. JL has a 6.5 inch w3, and tang band makes a nice sounding 6.5 inch sub also.
A fit guide will not help you with fitting subs there is not "factory" sub box that will fit unless you get those special boxes. But anyway you still haven't told use what car it is, basically any sub will fit dose not matter what a stupid fit guide will say. If you are that worried about a fit guide go to crutchfield.com. If you still need help pm me and I can help you out.