Where to mount crossovers?

[Turbolader]

I've done a search, but haven't found much. Just curious for people that replaced their front speakers with components, where did you mount the crossover boxes? Is there room in the door panel? If there is, is it waterproof?

I watched an install video from BSW and it appears that there is some sort of water membrane/vapor barrier between the door panel and the "weather side" of the door (where the water would drip down from the window).

If you mounted the crossovers inside the car, how difficult is it to run new wire through the door? Some cars I've had were pretty simple whereas others I've had to drill out interconnects between the door and dash/hinge post (Not much fun).

I guess while I'm at it...Is it worth putting some dynamat on the door near the driver? From the BSW video it looked pretty pointless because of all of the strengthening webs.

Thanks for any info you might have!