Sorry for all the banter. Everyone thinks they know more than everyone else about automotive speakers and sound, sometimes tempers get the best of us. Anyhow, back to the business at hand. If you want a solid tight bass that sounds true to the music, go with a midsize sealed enclosure. And no, two 12's isn't normally too much, unless you don't amplify the other 4 speakers, than may be. Rule of thumb is that you can always turn the gain down if its too loud for you, but not up if its not loud enough.
