i have a 2001 gmc serria extended cab, and there is not much room in the back. here is what i want, a box that fits under the seat that can hold 4 - 10" JLW7's my main question is can it be forward firing? if not how much do you loose when you set it to fire downwards or upwards toward the seat? i would get rid of the seat but i need it . any suggestions? anyone know of a solution?