Hello, I am a fairly new member, and very much enjoying the forum. This is my first attempt at posting a new thread, and hope I am not duplicating an issue already addressed somewhere else (although I have done my best to check, and have not found anything). My CLK W209 does not allow me to use the comand navigation. It always says "insert DX disc/read error". The disc was quite badly scratched and I tried to repair, but no luck. My friend had the exact same disc for his mercedes (which works fine), and I tried it in mine but again no luck. I suspect that it may be a problem with the lens inside the unit. When driving along, I sometimes check using the Nav button and on a couple of occasions the navigation would work fine, and sometimes cut out on me when entering an address. However, I have not been able to do this since. Please could someone help in finding a solution so that I am able to utilise the in-built navigation . Thanks.