Have to confess that I am now confused, and cross eyed after going through so many forums. Help needed for this newbie!! My car (well -- its the wife's car really -- honest!!) is W209 first registered 28/5/2004. It has a DVD Sat Nav system that has I believe the original DVD (Version 2.0). Is it worth buying the latest disc (I believe its £196!!!) or do I just stick my Tom Tom on the dash and be done with it??