Last Friday, October 27, I took possession of my 2007, made to order, Vista Blue Mustang GT with a manual 5 speed, 3.55 limited slip differential. In the first day the differential failed - a whine in the rear end turned to a serious mis-meshing of the pinion and ring gear in the first 100 miles and I retuned it to the dealer for repair. I'm sure they will do all they can to make it right, but how do I protect myself if they can't? Is this a known problem others have had? Who do I contact at Ford to complain? Can I demand a replacement vehicle? I bought the car in Maryland and the VIN is 1VZHT82H975261973.