2006 Ford Mustang car not cranking

When you say ot worked with slamming the hood I would check the starter solonoid or the starter. When it happens have someone just tap the starter lightly with a hammer. Even though things look good and clean sometime a little rust or dirt could do it. If not then suggest have the system scanned

I am not much in the computers but look at the pratical side. If the car does not start and someone shuts the hood hard and the car starts. I look at a bad solonoid, bad brushes in the starter or a broken or corroded wire someplace. If the key chip would go out that would be it until you bought a new key with a chip and had it programmed to the car. I feel the alarm system would do the same. I am not saying it's not possible but Working at a auto auction for a couple of years had to have a seen a few alarm system reprogramed and new keys made up. There is one thing. Do you have two keys for the ignition? If you do try both of them to make sure they work.