I was thinking of something after having read the posts from members who are modifying their engine air intake systems. Forgive me for being dense, and maybe the answer is obvious, but if getting colder air into the engine is good (i.e., because it's denser than warmer air), why isn't the intake air piped in from the passenger cabin? Alternatively, why can't the intake be set up so that it can take in air from either the outside or from inside the cabin, switchable by the driver? For at least half the year, the cabin air would likely be cooler than the outside air, so it seems like setting up the cold air intake to take advantage of the cooler air in the cabin would make sense.
Thoughts?