I'm not tech savvy , I've been reading in the forums about adding speakers and such , my question is : I want to add 2 extra speakers maybe under the back seat or in the trunk , I should add a amp yes ? Is there one that plugs into the cigarette lighter instead of going through the battery , I want to try and do it myself . I know to open the door panels and connect the wires through the back speakers in the door. I have 6 by 9 pioneers from a previous car . I want to make boxe for them to put under the rear seats . And or can I use home speakers? Any advice would be greatly appreciated !