I asked about the plugs about a month ago and got some good feedback. Pretty much people said the Boschs were not worth the extra dough. Those that had tried them in there KL03's said the NGK's ran better and switched back. I dont really know if it makes a differance for four bangers cause I didnt ask. I dont know about the wires, thats something I would like to know as well. Hope that helps and you havnt spent the extra money on the Platnium 4's.