Recently purchased a 2006 X5 4.4i. The NAV screen is kinda smudgy/cloudy. It almost looks like the previous owner tried to clean it with something he shouldn't have. Is there anything I can try to clear it up? If not is it replaceable (last resort). If so is it costly?

Also...how does one get the latest NAV DVD?

Thanks!

__________________
DaveC
2005 BMW X5 3.0 (current)
2008 Mercedes ML 350 (current)
2005 BMW X3 3.0
2002 BMW X5 3.0
1999 BMW 323i