Neko-

You're probably thinking of this TSB: http://mustangsdaily.com/blog/2011/03/31/ford-issues-tsb-for-2011-mustangs-to-resolve-cold-shifting-problems/

Wow... 600k, that's a lot of distance!

Orderguide can be found here: http://www.blueovalforums.com/forums/index.php?/topic/42052-2012-mustang-order-guide/