Any of you guys seen those Matts Juggernauts? My brother used to have a '97 Jimmy. He had one 12" in the back in a box that was specifically designed for a different sub, so it wasn't the best combo, but anyway, we pumped 4,000 watts into the sub (I think Matts rates it at 2,000 or something, which is ultra conservative. We've had as much as 8K at one point without any damage). So, at half volume, the windows would flex and it was seriously almost impossible to breath in the vehicle. We had to roll the windows down and even then it was difficult to breath. That thing was nuts. My brother's new project, however, is 4 15" Juggernauts in his '02 Avalanche. I'm waiting to see how it turns out.