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If you're gonna spend the money and buy something new, get a K&N or a JLT... something plastic. Idea behind plastic is that it will absorb less heat -> cooler intake air temps. Personally, I bought a used BBK fenderwell system. Looks good, but I sure don't feel a difference - not that I was expecting it to, but still.
To be honest, I've yet to put something on my car that's made any sort of difference via the butt dyno.