I was heading back from an event when the Tbird cut out. On the side of the road I isolated it down to missing spark. Embarrassingly it came home on a flat bed. I had a quick look but it was getting late so I left it until the next day. When checking it the next day I discovered it had spark again so turned the key and it fired up. 
I'm thinking coil failing when hot. What is the consensus out there on what went wrong?