Very interesting experiments. Subscribing for interest. I just rigged up a tube on my Fit to pull warmer-than-ambient air into the intake from the general vicinity of the exhaust manifold, and initial results seem to indicate an improvement over the absolutely dismal MPGs I was getting in December with the stock kinda-sorta-'ram' CAI.
If control over IAT is what you are after, how about adapting a heat riser system from a 70's - 80's American car? Basically, they draw air either from a hose connected to a metal box over top of the exhaust header OR directly in via the air cleaner snorkel; a vacuum-operated flap determines which. You could use a cable to control the flap. Here's a picture of what I'm talking about.
