All this energy needs something to couple the EMP energy to the device (radio, computer et al) in question. You can call that something an antenna, but it will probably be something like the wires in your house or the high power lines that run power through the grid.

I've heard that cars are not as susceptible as some think because much of the electrical system is inside a faraday cage (the car's body). I have no idea how that will work in the presence of a real EMP, but I think that geometry and location will have a lot to do with whether or not any specific car goes TU.

On the subject of Faraday cage, you can use one to protect yourself. Make one using metal screen and keep your sensitive gear in that with no power lines or other cables running into the cage. All you need is to prevent the EMP from coupling to your electronics -- sounds simple?