I ended up buying a cracked copy of both the Grey/White v4.B1 discs for $40. They installed and work fine in my 2012 CT. There's a trick to get the software to update, but it's very easy to do. There's no way I'm willing to shell out $180 plus shipping for navigation updates.
Last edited by WeirdG; 01-22-2013 at 03:44 PM.