Hello everyone, I'm still trying to decide whether to buy one or two FI 15 BTLs. I will be buying each sub with: dual 2 Ohm, cooling package, HiXmCoil, I heat ring, and will be set for daily. For each sub, I was planning on either running a Hifonics BRZ3000.1D Pro with 3,000 watts RMS @ 1 Ohm, or a Memphis MC1.4000 Mojo which has 4,000 watts RMS @ 1 Ohm. Will the FI BTL 15 be able to handle 4,000 watts? or will the 3,000 watt amp be a better choice? Money is not an issue, and I'm going to do the Big 3 under the hood. I am also looking for the dimensions of a box for either the one or two 15s. The truck is a 2009 Chevy Silverado 1500 extended cab. I'm going to remove the backseat, to make room for the sub/s. I don't know the dimensions of the back with the seats removed. For a ported box, FI recommends that the box is 3-5 cubic ft. @ 30-35 Hz with 12-16 square inches of vent area per cubic foot of volume. I was thinking of something around 4 cubic feet @ 32 Hz with 14 square inches of vent area per cubic foot. Can anyone find a link to box online, or show me dimenshions of a box that will fit in the back of the truck (both, a single 15" sub box and/or a dual 15" box, would be very much appreciated)? Much thanks in advance.