Hi newbie question. Does anyone have any recommends for someone to supply and fit audio upgrade to the factory head unit around Manchester, Cheshire. I'm not sure exactly what I need so I need advice as well. I'm looking to just get a better sound than the standard factory but not sure if I need to just add speakers in the back or I need new ones in front and back or add an amp as well as the speakers. Thanks for any ideas or recommendations in advance