There was a time when owning a car meant understanding it. If something went wrong, you could open the bonnet, look around, and at least have a reasonable idea of what you were dealing with. You might change a bulb without consulting a manual. You could replace a battery in minutes. An engine bay had wires, belts, hoses, fluids and mechanical parts and while it certainly wasn't simple, it felt understandable. Then cars became computers. Follow Car Guru DIY Blog Today, even an ordinary family hatchback can have dozens of electronic control units, multiple cameras, radar sensors, touchscreen displays, driver-assistance systems, wireless connectivity and software controlling functions that once relied entirely on switches, cables and mechanical components. Modern cars are undeniably more capable than their predecessors. They are safer, cleaner, quieter, faster, more comfortable and generally more efficient. A brand-new car can brake for you, keep you centred in a lane, warn y...