The part in question is glued on. However, there is no need to look in there because there is nothing to modify. I did some measurements on the K&N filter and compared this to the Benz filters. The K&N's are smaller and increase the effective size of the airbox by 24 cubic inches. That isn't a whole lot (maybe 5-8% larger), but it may help in some minor way. Someone could always increase the size of the plumbing going into the airbox if they were inclined. That may help a tiny bit and it would be inexpensive. Benz's are known for having sensitive MAF parts and many sensors have been ruined by oily K&N filters. So go easy when cleaning......