Vacuum connected and tested successfully! Per my earlier post, continue to follow this white plastic tube. It runs from the back of the car, up the drivers side and right to the fuel breather valve. Guess maybe it's the fuel breather hose!? In any case, it's the perfect guide/route.
To get the vacuum line from under the car to the engine bay, remove the rear half of the wheel well liner and the front couple of driver side splash felt screws (under and behind the front wheel) so that you can see what you're doing. Then zip tie your vacuum line to that white hose as you feed it into the engine bay.
After removing your plenum you will see the vacuum source. It's the "J-shaped" rubber hose that runs from the fuel breather valve to the idle control valve. I found it easier to remove the fuel breather valve (hose comes off the back and plug disconnects) and the vacuum hose from the idle control valve to install my tee. The oem black hose is 5/16" and the supplied blue hose is 1/8" so you can try to find a tee with reducer, or buy a junction and threaded barbs like I did (and this is what I saw others doing for exhaust and supercharger installs). There is plenty of room.
I still need to button up the vacuum routing with a few more zip ties and then run the controller into the fuse panel. I also need to mount the valve and solenoid, but it works great. More pictures to follow as I get it buttoned up tomorrow.
Video of cycling the valves during cold idle:
Photos of vacuum line routing: