Is it a car or a computer? The role of microprocessors in modern cars

When you look at a modern car you wonder how much its "nature" is computer versus mechanics driven. Cars built today typically contain many many microprocessors organizing specific functions and features of the car, e.g. engine management, in-car-entertainment, navigation, air condition, airbags, memory functions, ABS, ESB, ASR, etc. Modern car don't work if these computers are not doing their job. The complex hybrid system of a Toyota Prius for example asks for a lot of computer driven management to combine the two engines and decide on when to use the electrical motor to load the batteries versus to use it for acceleration. Computers are calculating the amount of fuel and air to go into an engine for every stroke, optimizing fuel consumption and emissions. So, as cars got more efficient and clean, more computing was required and the innovations were enabled by the power of the microprocessor. And with the ever increasing performance of these little computers (doubling every 18 months) more and more can be done with these. Soon these little "helpful hands" will probably even help us brake or steer should we forget to do so, computers can even control a car all by themselves. But this is research stuff and only used in the labs for the time being.
Computers in the car are a blessing as they bring safety, economy and convenience. But they also make cars complex and detach the driver from the mechanics and physics for the true driving. That's why I love old cars in my spare time while enjoying the innovations in my daily driver when being on the road for professional reasons.