We purchased a 2011 Mustang with the 3.7L V-6 in June. In August, we started noticing a tapping sound under the driver's side cam cover. Sound got progressively worse so we took it to the dealer this Monday. Upon removing the cam cover, the technician noted visual damage to two of the followers. Data was reported to Ford. Just got off the phone with the Ford dealer. Ford now says they are aware of a problem with the 3.7L V-6 with regards to early failure of the followers. They have no solution and they have instructed the dealership to put the (damaged) engine back together and give the car back to us until they figure out a fix. Thanks for nothing Ford! I guess they didn't have enough money to do real testing and their business model is that the Ford customer will do their durability testing for them. Meanwhile we're stuck with a brand new car (~6K miles) that has a bum engine. Ford just lost a customer forever.