yeah, I'm frustrated also but with ford. I have a 7 yo superduty with 30k on the clock. just stopped running and no one can repair it. intermittent problem, will sit in the drive for a week and won't start and one day it will and run for a day or two and quit again. of course it never does it when its at a mechanic. dealer has no clue, several decent mechanics have no clue. I just got it back from another shop 90 miles from the house yesterday. we'll see if it starts this morning. he kept it for a few additional days and it was working. I'm in for 3500 bucks so far. so I feel your pain.
I've read stories about bad, intermittent, PATS keys. If the chip is broken or bad that can happen. Maybe try a different key. Especially if you give a mechnic a spare key and they can't make it fail but it sometimes fails with the key in your pocket. A bad ignition switch could be the culprit too.