In my case, it turns out there just wasn't enough room behind the door panel unless I wanted to install it inside the door cavity (where the window regulator is, etc). Maybe CDT's crossovers are abnormally large.
I wound up fitting them behind the kick panels. Just finished everything a couple hours ago. Here are the specs now:
Pioneer P80MP head unit
CDT HD62 components in the front
CDT CL6 midranges in the rear
Audiobahn 6004T amp (75Wx4)
Image Dynamics IDQ10v2d2 10" sub in a 0.6cuft sealed enclosure
First two amp channels power the fronts, the last two are bridged and power the sub. The head unit (running in 40W mode) supplies the rear midranges. Not sure I like the Pioneer's user interface but I'll give it a few days before I decide whether to keep it or not.