What is something that could go wrong with a car that would cause it to suddenly just stop working, on the middle of a highway, and that a reasonably car-savvy person would not be able to just fix with the tools available in the car? (I.e., not a blown-out tire, because she could just change it herself.) But also something that would be very easy and quick to fix if you did have the right tools/parts?
Ideally, it would be something that could plausibly still exist in an all-electric-powered car (not a gas/electric hybrid). For example, I was thinking of having the fuel injectors fail, but an electric car wouldn't have fuel injectors, right?
As you can see I know very little about cars so any help would be appreciated.