What I meant was that the pro design pro flow kits are pretty much the best air filter "kits" out/with air box.Half of the point of them other then better air flow over stock is you can take the lid off without worrying about the air filter falling off or whatever causing a leak.The air box lid holds the stock air filter in place.
A lot of people run there banshees without the lid.I would take it off IF you were going to buy the pro design foam kit, just remember you WILL have to rejet an like Bsock said the foam filters clog up relatively fast.