I was thinking because there would be more air space inside the box versus having 2 10" W3V2's.

 

No, 1 would not be better. When it comes to subwoofers, more air space doesn't mean better. You want to provide the optimum box volume for the particular sub. 2 10w3 would be louder. Their optimum enclosure size is .625 cu ft. so the large zenclosure box would be about right after displacement.

 

It will probably sound better/balanced out, but not going to be insanely loud. Unless you got upgraded front speakers then you would drown out easily on 2x10s.

 

Like will4992 said, one will sound better. From experience . I had two of the exact subs in my Z. Sounded ok with the windows up, but when I would crack the windows about 1", and then they would come to life! That's a very clear indication that your enclosure is too small for your subs. If you insist on having two, one thing I did that helped until I bought a different box is to mount the subs inverted. Meaning magnets out. By doing this you are freeing up a little air inside the box that was once displaced by the subs. It was still too small for the subs, but it helped for a little while lol.