Have you ever had a song stuck in your head to the point where you just need everyone else in a six-block radius to hear it? Apparently that’s a common affliction in my neighborhood. Last time it was Paul Simon at 4 in the morning. But at least they were only playing it on a boombox, not a 4000-watt sound tank. Berlin-based artist Nik Nowak has created an actual track-based vehicle, as in a tank, with over a dozen speakers on it. Built on the frame of a Japanese industrial dumping vehicle, *Panzer *is the final answer in the boombox wars.