The problem with segregating it within the engine compartment is if you do it wrong, you're actually restricting airflow to the filter.

For the money you're going to spend on developing a cold air intake for minimal gains, you would be better served with spending that money on a water/methanol injection system. You will see better performance gains there for less money than you're going to spend trying to engineer a solution where there really is no problem/restriction from the factory. With the WI, you will get more torque, see less detonation on hot days & keep the inside of the motor clean as a result.