I really want to fit rear speakers to my n15 sedan. But the car didn't come with rear speakers. So there is no hole i the parcel shelf and looking from the boot there is no speaker wire insight. So I went up to the radio and looked at cables behind there and there is a set of 4 wires that goes to the rear speakers. Now I just need to know where these wires are hidden in the car. Does anyone know that?? Another question: I can see that under the parcel shelf there is 2 big round holes in the metal for speakers and 4 small holes for the screws. Looks like 17 cm speaker holes, they're not oval. So does that mean I just need to cut two 17cm holes in the parcel shelf and that should do the trick?