Bingo.
I like how so many people here are worried about an EMP yet clearly have no idea how they work. Even though we have so many very smart engineers.
All an EMP does is create a large current through devices for a very momentary period of time. The only way said device is damaged is if the current is enough to can a ground or short of some kind due to being beyond the current-carrying capacity of the materials. So - yes tiny little circuits that have very very small wires - e.g. microchips - can be damaged. Especially if they are currently carrying electricity (e.g. "on"). But larger-current carrying circuits, like starter, plug wires, hell most 18+ga wires on vehicles would require a HUGE magnetic field to induce enough current to damage them. And by huge I'm talking like MRI machine kinds of levels.
Now in order for "the whole country" - or even some small region of it - or even a single town - to be affected by at that level, the source would have to be ridiculous. And at that kind of level, us biological creatures will have much bigger problems than your car not starting - if your whole brain were exposed to that level of field all simultaneously you'd end up having seizures at least and permanent damage at worse.
Go look up TMS (Transcranial magnetic stimulation). Popular technique for inducing and interrupting brain activity.
Think about this - how do heart defibrillators work? Yes that's right. Same thing.
Trust me - a wide-scale EMP is no more of a problem for societal collapse than being invaded by laser-wielding aliens. They can be great "tools" In a focused sense but nothing like in the holocaust movies.