Looks good. I found a shop that does it all around with warranty for $129. I'm thinking about getting it done. Im going 20% though most likely, scared to get pulled over. Can you tell the major difference in tempature when you get in the car?
Like blaze said, add more power since your going to have to use a smaller enclosure. Your current box is ported correct? Cougars are pretty small, so I'm not sure how difficult it would be too fit an extra sub ported in there.