If you do forward facing subs, be aware that you will lose impact as the subs will be firing into the back seats. You can drive around with your rear seats down or do the spacer mod: Rear seat spacer
If you front fire the subs you definitely need to seal the front of the subs to the cabin, so the waves cannot bounce back into the trunk, being reflected there and cause cancellation issues in the cabin due to that.
Generally speaking the bass gets better with rear firing subs that are mounted as near as possible to the back of the trunk.