A true cold air intake only serves to ensure the air the engine is sucking in stays at the same consistent temperature, unlike the stock intakes or many aftermarket ones that heat up as the engine heats up the engine bay.
A true cold air intake would require you to have the filter outside of the engine bay.
They don't really add to your mpgs or hp at all, the realistic increase is maybe 1-2 hp with a good motor.
A short ram intake is pretty much just for the aesthetics. In fact, as far as functionality it will perform worse than a stock intake as it sucks up more hot air from the engine bay, and call suck up alot of dirt and other engine junk if you buy a cheap filter.
Your best bet would be either to remove the resonator baffles from the stock intake, plug up the holes, and buy a high flow filter for it; or buy all the piping to make a custom cold air set up. Just route the piping down into a wheel well or under the car. Just remember to watch for puddles...