04s already have a breakout iat i thought. Unless youre just implying an extensionthe stock intake already gets "cold air." even though the plastic parts get hot, they transfer very little heat energy per unit of airmass to the air going into the engine. that air moves very quickly, especially at high engine loads/speeds, so it's really pretty close to ambient as it enters the engine.
if you're going to leave it stock, just get a breakout harness and drop a stock IAT somewhere that gets airflow and that's as far away from the engine heat as possible. drop in k&n filter, and make sure the stock intake isn't missing any peices.
if you plan on modding, then get an aftermarket intake. the stock intake is only suitable for a stock engine.