My I have seen all types of cold air intakes and NONE of them sealed the hot air away from the inlet as good as the factory unit does. The oiled K&N type filters release a residue that builds up on the mass airflow sensor electrodes and your fuel mileage may actually suffer and outweigh any performance gains you might see.
I have only seen one that looked like it would work and the customer said he paid over $650.00 for the system hardly seems worth it to me
Gus