Engineering Puzzle of the Month

It seems that systems are becoming more and more complicated. The hybrid engine is the latest example. Though it looks simple to understand that the smaller internal combustion engine acts as a generator to charge batteries for an electric motor, the internal combustion engine is quite complicated in its self. Add to that the fact that the majority of the systems in a hybrid are managed by a more complicated computer with more layers of software and you have a quite complicated machine. It would take a true polymath to be able to work on all of the systems in a hybrid. In engineering the less complicated a system, the less there is to go wrong with the system. What would be the best way to reduce the complexity of automotive propulsion without going directly back to the internal combustion engine?