Interesting install.....when I started working on my E-150 the idea of mounting drivers that far up the pillars never even crossed my mind....
I mounted the tweeters from my JL XR 5.25 comps just above the top of the dash on the A pillars, the 5.25s in the factory locations and had 2 6" midbass drivers installed in a panel in the bottom of each door.
How do you find the front stage imaging? With those drivers that high up and in particular the one on the drivers side so close to your head, how was the setup and balancing process? I'm sure the 4"s take care of a lot of sound, what are you using for lower midrange and particularely mid-bass?
Any pics of the rest of your install? I thought I was the only guy who did up a full size work van.....good to know I'm not the only one who's into overkill on the road......