Being an Ozarker I'll try to get all the hillbilly credits I can get
Glad to hear that the window shaker works for you and I'm adding one to my van too, just differently.
I'm building a console between the front seats and it will hold my window AC unit. Inside the box I'll have three ducts, 2 fresh air ducts to the intake on each side and the rear for the condenser, a drain pan and drain will be vented out to the bottom. The AC will blow out toward the rear with the controls a short reach from either front seat.
The console will be insulated and sound proofed the best I can with accessories. It will still be low enough for us to crawl over from the front to the rear, gotta be able to get to the fridge at all times you know.
At least that is the thought for now. I'm trying to keep it stealthy.
All the best!