For me when I’ve tried to have small sealed enclosures in the past, it only lasts a couple months before I fill up the back with a large vented enclosure. I’m sure it’s mostly a “nothing is ever enough” character flaw on my part but I’d use the absolute largest enclosure you can live with from the beginning and avoid soon to come dissatisfaction with the output from a low profile system. This is what I had and while space was somewhat of an issue when I needed to haul my toolboxes or the kids Christmas presents, the remaining 95% of the time was fine. I will say that having a large woofer gives you the ability to adjust each song to the correct low end output while also reserving the ability to jam out when you like. For instance Third Eye Blind - Tattoo of the Sun’s low end just isn’t going to pop unless you have a large system with gobs of output, and there are many other songs like it where achieving the crisp punches on a lower output system means you are going to have to overdrive the woofer and the sound quality is going to suffer. On the other hand, and again this is surely a character flaw on my part, with a high output system the temptation to jam out and be “that guy” riding around with thunderous rumblings emitting from your vehicle happens more often then not.. That’s my 2cents :]