That's what I've done to mine. Makes it look a lot tidier. Also thinking about a lid for it so that it is fully covered, using the hole in the inner wing as an air feed.They look crap but work and if you're that bothered could just use the cardboard as a template and cut it from alluminium/steel
I have the K&N cone type induction kit. Never oiled it... are you supposed to?Only real issue is that the Apexi/HKS filters are dry types, where as the K&N is oil based.