if your planning on attaching the cone filter directly next to the turbo then its a complete waste of money , unless your planning on directing the filter to the front or making a new boxed off filter then id stick a new element in the OE airbox
using a cone filter and positioning it next to the turbo will lose you power as it will be drawing in hot air making the job of the i/c alot harder and inturn raising the charge temps, amazes me the amout of 5's i see with the cone filter pos next to the turbo