high flow air filters like K&N allow u to gain a few BHP more, and don't really affect your low-end torque. Also, they r washable so u save on having to throw away used filters and buy new ones. And since u r not throwing away filters, its more environmentally friendly too!
if u want a whole cold air intake, u must be able to install it such that it is able to draw in cold air. its no point if it is taking in hot air from the engine bay. U'll probably need to put in insulation to prevent that from happening. Also, most of your low-end torque will be lost.
