Air Filter box

[tuscanturner]

Has anyone changed the design of their air filter box or changed the air feed from underneath the car to something like the race cars used? and would there be any benifits from having a cold air feed from say the bonnet, wheel arch or front grill as opposed to underneath the engine?

My airbox is a little worse for wear (warped and splitting) so I would be interested in some thoughts for changing it and possibly improving it.