New stereo, aftermarket; the aftermarket stereo i had in there has a filter and fusebox which were part of its own wiring harness, but the new one i just bought doesn't. Does that mean I should add the old one in to the volvo's wiring harness, or just leave it out of the equation? This particular radio DOES have a fuse right there inside of it up where the wires connect. The new stereo's instruction manual (new used, of course) shows that those particular wires are to connect to the 'car's fuse box'. It seems to me that this black box labled 'filter and fusebox' which came with the old aftermarket stereo is no longer necessary, but i am not at all sure of this. Please help if you've an idea.

ALSO: anyone know how to wiring the darn thing? my car has two speakers, and after undoing the old connections i've lost track of what went where (the whole process seems unpleasantly inebriating), although i managed to connect the positive wires of each side correctly to each side's wire on the Volvo side. The thing is: where do the negative ones go? I'm all out of wires now on the Volvo-side. do the stereo's (-) wires for the REAR speakers need to be doubled up with the Volvo's (-) speaker wires? I got the wire diagrams but that ain't much help. It seems like a no brainer, but for some reason my old stereo didn't double up the wires but for the positive ones, yet i didn't have any odd wires loose. UM, does anyone know what i'm talking about?

THANKS YOU GUYS!