the bits and pieces of cars that squeak and rattle and break—everything from why is my wheel going clickety-clack to how do I get rid of this rodent smell. But for some time now we've seen our inboxes stuffed with questions on the failings of electronic components. That says something about the technological progress of the automobile. Vehicles are increasingly behaving like computers with wheels, so it's time for a discussion of a little-known aspect of your car: its computer network.