No doubt GB.
There are only a few countries(ours included) that have the capability of emp without an explosion. Dirty bombs and nuke suitcases can be set off for an emp but the area is very limited, actually almost mirrors the blast radius. So you are pretty well screwed unless in a fallout shelter if you live where it goes off.
The areas capable of reaching us and setting off a nuke in the atmosphere for an emp effect would be most of Europe,Asia and some of the Middle East. Strategically it would be wiser to allow the nuke to touch ground and wipe out people, vs. wasting it on the 16% chance of frying computer chips in cars and trying to wipe out an electronic infrastructure that still only theoretically can be done.
That being said, all I know how to work on is old vehicles. I don't own any with a computer. If you are paranoid of electronic ignitions, you can buy an electronic conversion for points made by petronix that uses a magnetic pickup. No circuit board to fry in it.
Truthfully I would be more worried about staying away from society in such an event. If you have a vehicle and others don't, odds are you will be killed for it in a survival situation. Actually if you have anything that others don't, or they even think you do, odds are there will be those feeding on opportunism.