Common problem. I have a 2006 and the unit works fine apart from Sat Nav which doesnt work and displays the disc reading error. At first, not knowing much about the car, I thought cleaning the unit and disc might fix it, but it didnt. Then I started reading about the fault from other owners and discovered that people have tried using other discs with no luck. The general opinion is forget trying to fix the problem, even if you could get it working the data is completely out of date. Advice is to buy a modern, portable Sat Nav unit, which is a fairly cheap solution and wouild be far better in its data content and operation. Or, take the unit out and replace it with a complete new modern unit, which is a costly option. I now only use the unit to listen to the radio and have a screen mounted Garmin Sat Nav, sometimes even using my smart phone in a suction mount and one of the many Map Apps.