In my opinion, I would go with bigger and better subs. The best is to get subs which are atleast 12". The diameter is necessary for the low frequencies. If you want to get better subs, but stick with the same size, then you should spend a little more on W7 b/c I wouldn't think the W3 are that much better then factory..if any. Not really sure. But I highly recommend the Diamond Audio subs. They have the most travel which allows for better sound. In addition, I believe they need very little in the way of required air space. You should check it out. Good luck.
