I have my stereo all together now and am about to pick up a car.
Car will be an integra, celica, camaro, or a probe (all hatchbacks)

Just have a couple questions after searching.
What is a good box size for a D9? I was thinking around 3ft cubed.
What tuning for a D9? Know they get good SQ, so I was thinking 32ish?
In a hatchback, what is the best sub/port direction? Both back, both up, mixed?