I don’t even play an Electrical Engineer on TV (though there are dozens in the building I work in), and I didn’t stay in a Holiday Inn Express last night, but I believe what SonsofCollins wrote is generally correct.
Cars may not all be dead, depending on which way they are oriented relative to the EMP source. There MAY also be a phenomenon that keeps the pulse from penetrating the gap between, for example the hood and the fenders, depending on the ratio of the size of the gap to the wavelength of the pulse.
Generally, it’s my understanding that conductors that are long relative to their cross-section tend to be more vulnerable; this would include both conductors on integrated circuits and long-distance power transmission lines.
Commercial aircraft, ironically, MAY be less susceptible, since they are designed to be resistant to lightning strikes, but if there is no way to navigate them or fuel them, that doesn’t do a whole lot of good.
Thanks ... interesting - a little scary, but interesting.