i've seen enough threads (1 or 2) about guys hydrolocking in heavy rain. who knows what their wheel wells were like, or what they did to their cars, but it's enough of a risk and not enough of a reward to warrant getting a CAI. Type S airbox or Short Ram + Cold Air box might be safer for those living in wet places.

Bypass valves costing you 1 HP leaves a net gain of around 1.2 HP to the wheels. :P we talking 1hp at the crank or the wheels?

and about dyno testing with open or closed hoods and the short ram: the ambient air temperature inside of the engine compartment at speed has been shown to be pretty much the same as the temperature outside. The airflow into the engine bay and the movement of air insures that the short ram pulls cold-ish air (depending on the weather). The only problem is when accelerating from a stop, when the air in the engine bay has been stagnant for a few and has heated up. I haven't done my own tests because i'm not sure i care that much, but a friend of mine who worked at DC said that told me this.

i have an AEM CAI. i like it. Don't think i'd want anything else at this point.