I got rid of my airbox, and have the air filter (the smaller version of the BHAF) just resting in place at the stock location. I noticed a very small reduction in EGT at cruising speeds (maybe 25 - 50 deg. F), and about 100 - 150 deg. reduction at full throttle.
The first gens are not nearly as sensitive to hot under-hood air as second gens because of the location of the air filter. On second gens, the air filter is closer to the exhaust manifold.
It's easier to understand if you look at the general pattern of airflow under the hood. When the vehicle's moving, air comes in through the grill, and exits below. This is the practical reason behind air dams--they enhance this flow pattern by lowering the air pressure underneath the vehicle, almost "sucking" the air down and out.
The second gen's air filter placement tries to take advantage of a higher pressure area at the base of the windshield. Cowl induction intakes that stick up through the hood on high performance V8 gassers work along the same lines. Well, those that are open towards the rear anyhow--not the "ram-air" style.
Theoretically with the placement of our air filters close to the front, the only heat we have to worry about is that from the radiator and other coolers up there. In my opinion there's not much to worry about since the air isn't being drawn towards the air filter--it's being drawn back and down.
What we really need to deal with this issue is someone to place about 10 small temperature probes all around the inside of the engine compartment, and take a bunch of data under all different type of driving conditions. Obviously that probably won't ever happen.
Mike
Attention: TDR Forum Junkies 
Howdy
. Didn't do much for EGT, boost or spool-up. But the K&N was covered with crap on the bottom half which probably didn't help. Since the K&N and the airbox will disappear shortly I couldn't resist hacking into the airbox. 
