As far as the box goes, building it yourself is really the way to go if you have the tools to do it. You can make it customized to your car, you can put better bracing than a prefabbed box will offer. There are some good ones out there, though. I'll try to get the company name. It's on a another thread right now.
www.sounddomain.com , maybe??
BTW, IF you go with a ported enclosure, definitely make it yourself unless you can find a sealed box with the exact volume you need for the sub. Then add your own port to the correct length. If you need help with the port diameter and length, let me know.
Dave
