bass tubes are not really suitable for saloon cars... they are designed more for hatchbacks or MPVs ie car without boot. as for the cc, i think if u want to create better bass, enclosed box should be used and instead of facing the woofer upwards, try pointing it downward (facing the magnet up) this set up will give you a very tight bass.
as for everchanging of ICE, if Da Boss is to show the pic, that is my version 2 of the setup... Version 3 is coming soon... (when??? probably when my pocket is not so tight)