the apollo intake, the flex tube that comes with it attaches to the front (inlet side) of the filter allowing you to mount the opening (to an extent) where you want. the filter itself is inclosed and mounts to a stock intake tube. the resonator is the biggest restriction just removing that makes a world of difference on throttle response (it did on my 04 anyways), but removing the stock tube and replacing it with a CAI or SRi tube improves the air flow between the filter and t/b (less chance of turbulance). short and sweet, remove resonator equals "MORE" airflow, replace stock tube equals "BETTER" flow. Im sure you already know this info petrified, but it may be good f.y.i. for others that may come across this thread