Woofer fires toward side of the vehicle, with the output aperature at the rear edge closest to the tail light.
This allows for some "loading" of the speaker and protects it from objects in the truck area. We've had a lot of good luck with this type of loading on other Stealthbox designs. If the woofer were down-firing, items put into the trunk area could restrict the output of the woofer. If the woofer were firing forward, it would require some kind of gap, or aperature, and that might look strange. In the configuration I've chosen, the woofer output does benefit from loading off the rear hatch since the aperature is right at the hatch opening area in the corner of the trunk.