Installing sub and amp on clk350
http://www.parts-express.com/cat/car...18;25418|25418
So, what you would do is splice the new amp in between the factory amp's speaker outputs and the speakers.
I know this sounds kind of strange, to take a pre-amp signal and amplify it, just to drop it back down again, and then back up, but that's the least expensive way to make this work. For cars like yours (MY2005+) that use the MOST fiber optic system, you can buy an adapter that converts the fiber signals to pre-amp. This would basically mean you could totally remove the factory amp and use your own without all of this high/low/high conversion. Here's an example of such a converter:
http://www.autotoys.com/x/product.php?productid=16059



