The reason why some of us are leaning towards active isn't so much about SQ, but just opening the door to speakers with more "oomph" to get the front stage output closer to the sub-bass output. Another thing that hasn't been addressed, and can make a very big difference is sound deadening. Aside from quieting the door panel so it doesn't rattle, you want the panel that the speaker is mounted to to be sealed as much as possible, otherwise it'll kill your midbass. IE: http://blog.stefanhi...1-51-46_959.jpg Notice the large opening to the right, and various holes. I covered those up with cld tiles, then applied a sheet of mlv over it: http://blog.stefanhi...2-47-48_674.jpg So with some slight dremel work to the door, is 6.5" the largest speaker you can fit? Next, what about depth? Be sure to measure with window glass down. Any room for using spacers if depth becomes an issue? If so, how much?