There's some interest gathering on the other various forums for these, and we might consider making them if there is enough interest for at least 20 pre-orders.
We've had a prototype built for over a year, just haven't had time or resources to get them produced. The prototype is going in our 2009 sponsor car, so we should have some pictures of it up soon. We may produce them if there's enough interest for at least 20 units. Haven't really had time to give it much thought yet.
Here are some pics of the prototype we have to give you an idea. It's all fiberglass and fits right in where the stock storage box would normally go. It's made to use two 8" subwoofers. It's molded to fit perfectly against the firewall and center console/armrest:
