Computers are not interesting in and of themselves except to a handful of their users, and those users will educate themselves whether they get help from public education or not. That means networking, multimedia, and databases, not simulations or programming. By analogy, no mandatory training is required for information technology, specifically computers, if it has an intuitive and friendly interface. This argument is based on an absurd premise.
Cars are complex devices used in a complex environment.
Most governments require some level of certification for all operators of motor vehicles on public roads, which may include mandatory training and almost always includes some kind of examination. Other users of public roads, such as pedestrians, also require a minimum level of competency to avoid dangerous situations that arise as a result of motor vehicle traffic. I for one received such training many times during elementary school. In addition to this legally-required, minimum competency, most drivers understand issues such as basic maintenance schedules and performance monitoring related to cars. By understanding these issues, drivers have an improved overall driving experience, avoid being an inconvenience to others, and even materially improve the safety of the whole motor vehicle environment.