I dont see too many people use Focal for the subs for whatever reason. I bet they are very nice. And yes, quality is 100,000,000 times more important than quantity for bass. Thats why I went with a sealed enclosure myself, and a 10 inch sub. For those new to car audio, the smaller subs are tighter and faster. They won't impress your friends as much as 15 inch subs, but they are (imo) the audiophile choice. But I wont deny that there is something impressive about a ported 15" rocking away shaking your rib cage
One of these days I need to get a capacitor. I dont have headlight dimming at all (strange, since my engine is 4 cylinder, and my old dodge intrepid 6 cylinder had dimming; I attribute that to the new kinetic battery) but I want the SQ benefit of a cap. (Better voltage stability)