I recently did a Cadillac Escalade ESV for a buddy of mine with (2) Fi BL 18's with the flatwound coil and cooling option. Built the box to 14.63 cubic feet with the port tuned to 33 hertz. Wrapped it in vinyl to match the interior of the vehicle and did a big "Fi" logo on the back of the box (notice the logo is an "innie", not an "outie".The amp, for now, is a Hifonics BXI2010D that puts out 1752 watts RMS. I will be swapped with a Rockford Fosgate T40001bd eventually. Built to be a daily driver. Here it is: Sounds great. Real nice quality and it really hits the lows nice, but it just isn't near as loud as it could be with the right amount of power going to it.Even still it beats pretty nice.Shakes the whole dash up and down and can hear it coming about 150 yards away.