True, they could significantly change manufacturing dates. If it were earlier, Ford would have to let you out of the PowerLease early with no penalty. If longer, they would have to extend the lease with no penalty and possibly offfer an even cheaper price per month. You are, after all, essentiallly releasing a used vehicle. I actually bought an 04 Cobra about 5 weeks ago and after they changed the computer 3 times due to electrical problems, the dealer converted me into a PowerLease. Sad to say, I'm still having electrical problems and they can't find the source.
Having said that, I made sure the PowerLease was in my best interests.