I think what you mean is the engine top breather that connects to the throttle intake pipe . I wouldn't bother for a road car,it only filters dust particles,and sucks in moist air when engine cools,and moist air contains water etc.... That is why there is a one way valve there in the first place.
BBS are a pain in the A*** to clean ! I'm looking for a set of 7.5x15 five spokes at the mo. Hellraiser,what's that on the right rear passager side window ?
Get the Hi Fi dealers to give you a demo.If you can't Hear the difference between your cable and oxygen-free ,then don't buy oxygen-free or if your hi-fi is crap ,using a pair of £200 cable ain't going to improve your sounds.Let your Ears tell you which cable you need .Happy listening.
I think the bolt that you see at the back of the cage is only a locating bolt , what is holding the cage are the tabs at the front of the cage,lift thoes taps up (top,bottom,lift,right) and slide the cage out.