I joined the warm air intake club today. That is 4" dryer hose. It was quite a challenge to stuff that hose in there, not much room in the engine bay with the V6. The hose is sucking air from right by the pre-cat.
Someone with previous experience with warm air intakes should chime in, but I expected to see the intake temperature rise fairly quickly. It was 55F outside and I hit 100F coolant temperature before the intake temperature even moved. The highest temperature I saw was 57F over ambient, which is definitely higher than normal, but not by much. My usual scangauge setup does not include the intake temperature, but I have run it before and saw 40-50F over ambient when frequently coasting in neutral.
I only took it on a short drive, so I will have to report back later with the full results. The tube wasn't as close as it could be to the pre-cat, so I moved it a little closer, but I probably need a shroud to get the full effect of the exhaust heat.