Well... I Built the box and guess what? I can't get it into the trunk, lol. Boy was my friend happy when he heard that, he rushed right over and upgraded his sub woofer box for his Tahoe =) It's not a total loss. I'm amazed at the difference between the 3 cube box he had and the 4 cube box I built which he now has, INCREDIBLE!!!
Back to the drawing board. Not sure If I can get a vented enclosure of that magnitude in my trunk. If it were less than 13.5" tall I could have slid it through my back seat into the trunk. I think I'll have to settle for a box that's 13.5" tall x whatever and slide it into the trunk. Now I just need to figure out dimensions and go from there. I should be able to achieve 4 cubes in a sealed box. It was good practice building that last one. Makes me want a hatchback or SUV that's for sure.