Just all around. Two 12" subs in the same box OR 2 12" subs both in their own boxes placed in a v towards the front of my trunk. Front being where it opens.

 

woudnt matter.

 

okay, just wondering since I think I like the separate boxes more

 

2 for wouldn't matter

 

2 separate boxes will let you take one out if ever you need the extra space, yet keep some bass with the single sub.

As far as a difference in the sound each setup will make, I'm with the other two guys, it'd be so slight that you probably wouldn't be able to tell the difference.