Recently my Volvo's CD player has started acting up. It won't play CD's at all. I have started looking at a few aftermarket replacements, but I noticed one thing with all the head units that fit my car. THey are all 4 channel, my car has 8 speakers. So obviously that's half of them not being used. How would i go about hooking all 8 speakers to the deck? What else would I need besides the HEad Unit to go about setting this up. I hate to say it but the stock Volvo Unit was pretty amazing for stock. Does anyone have a good Deck in mind?