Thanks a ton guys for the info, and for the link in the last post.
Just to clarify, I'm not really sure as to what I want in terms of ported vs sealed, standalone vs mounted. I don't really have much preference of powered vs passive, but I understand powered will be easier.
Is the difference between ported and sealed like it is in HT subs (to the same degree?), or not? I'm going to have a lot of space in my trunk, seeing as the car probably has the largest amount of space aside from maybe an Excursion.