I've been dreaming of doing this mod as well, mentioned it awhile back. I was planning on using the 4runner stuff, it's good to hear that's been done on a rig before, so I know I'm barking up the right tree. As soon as I make it back to PnP, I'll pull one of the 4runner window regs and walk it over to one of the 620s in the yard, see what kind of fitment/clearance isssues there may be. the way I envisioned it, make a box that bolts to inside of cab so as not to disturb the bodyline outside. I believe it can't be done, and look clean. And you're totally right about the airflow, think how awesome it would be w/ all 3 power windows comin down at freeway speed... hold on to your hairpiece! Thank you for refreshing my drive to pull this off, and if you dive into it, I'd love to watch the build thread.