yes and no, there is going to be chance of it getting air in but then it may draw in hot air, so sorta defeating the object. although i did see a review on filters on a rst once where they tested the filters and also tried drilling the box, drilling the box gave a small gain in bhp and a slightly bigger increase in torque( if i remember correctly ). but u might aswell do it as u aint gona lose anything by doing it ( except maybe an airbox). one thing i do remember is that the box they drilled was basicly just a carcus left

anyway enough rambling on...... hth