Ok I've got it fitted and it sounds awesome and makes the car shake.
I've got a couple of questions if anyone can answer them...
If I turn the bass up too much will it cause hearing problems? Or will that only happen if you turn the volume up too much? Will this also damage any part of the car like the windows?
And how can I get the best sound? I want clear vocals and clear but powerful, vibrating bass. There's "level", "low pass filter" and "bass" controls on the sub, can I change these in some way to improve the sound? Also my car has an EQ built in to the CD player and you can control "bass", "treble", "loudness".
Also, can I balance the bass to make it have the same level of volume throughout the car instead of the bass being extra loud for rear passengers? I have a setting on the car that will let me fade the sound to different sections of the car (e.g. front left speakers, rear right speaker etc.)