At the Barrett-Jackson Auction I spoke with Jim Schenck about the AAIC in my 818C. He said FFR had made ducts for the side vents that he would send to me if I would install and give feedback. He did, and I did. I made a plenum (air box) that directs air from the 2 roof ducts and 2 side vent ducts to the stock WRX intercooler. My plenum has 2 SPAL fans inside, on a switch, to push air when in traffic, and I mounted an Intake Air Temp (IAT) gauge on the front of the plenum that I can see in the rear view mirror:
Plenum installed.jpg
On the inside, I made walls to separate the air sources so they would not compete:
Plenum internals.jpg
And, the IAT gauge shows the hot pre-IC temp and the cool post-IC temp.
IAT gauge.JPG
I drove 850 miles round-trip to Huntington Beach last week and ambient temps were up to 90 degrees through Palm Springs, but the post-IC temps stayed under 100. Today, at home, the ambient temp was 72 and I tromped on it to get the pre-IC temp up to 180 degrees. The post-IC temp went up to 120 then quickly dropped to 95, so I think it's working.