DB12's: Which box design?

[LittleCar_w/12s]

I am about to build a custom box to match my Older Polk DB12's.
It will be a dual sealed enclosure to fit my car, but I have a few design questions for you long-time guru's.

Airspace will be .88cu.ft.

1: Basic box design?
- tall wide box, but box is not very deep?
- Deeper box, (just fits 12's into face)?

2: Angle of driver?
- box will be angled to fit back seat angle, sub will be facing directly back
- sub facing slightly angled upward
- both back of box and sub will be flat (square-ish box)

Thanks for help.

[LittleCar_w/12s]

I'll make a diagram of the rear of car if ya need it