That's a bad example. My BMW E90 has a gasoline direct injection system, which was state of the art when the car was made 9 years ago. It is very complex and the parts it is made from are very expensive. The BMW specialist tell me the misfire my car has will therefore cost more than £2500 to fix, and even then they'd be guessing.
It would be better if car engines were simpler, like they used to be before they had to start passing artificial emissions tests that don't measure the impact for the whole life-cycle of the vehicle.