Some owners of 2011 Mustangs with the 6-speed manual transmission have complained about shifting problems when the car was cold, and Ford has issued a Technical Service Bulletin (TSB) to address the problem.
A TSB is not the same as a recall, but customers who have this problem can take their car to the dealership and they will fix it for no cost to the consumer. The fix involves swapping out the full synthetic transmission fluid and replacing it with dual-clutch transmission fluid.
The procedure should take about half an hour.