Back in the 1970s, the newly established Environmental Protection Agency (EPA) issued standards for vehicle emissions that all American car manufacturers were required to meet. Because of this mandate, car makers began using electronic equipment to control vehicle functions.
This new equipment dramatically increased the complexity of the systems found in automobiles -- and dramatically increased the cost. A 1968 Toyota Corolla, for example, went for about $1,700; the 2009 model started at around $15,000 [source: Edmunds, Cars.com]. This complex system has vastly improved vehicle performance, safety and fuel efficiency, but it has also increased the likelihood of breakdowns. The more interdependent parts a system has, the higher the probability that the system will fail, after all.
The on-board computer has made troubleshooting much easier when something does go wrong, however. During the 1980s, a universal system was established by the Society of Automotive Engineers (SAE) for cars known as the On-Board Diagnostic system (OBD-II). They became mandatory in 1996. When something goes wrong in a car outfitted with OBD-II -- you'll know when you see that "Check Engine" light flash on your dashboard -- a mechanic can plug into the computer and receive a code. This code is then cross-referenced with a handbook of codes and their meanings, leading the mechanic to an accurate diagnosis of the car's problem.
Thanks to OBD-II, car repair can be less expensive, since trial-and-error isn't necessary. On the other hand, when something does go wrong, the cost of repairing a modern car can be more expensive than it was to fix an older car a few decades ago. The more complex modern engines require designers find creative ways to pack more stuff under the hood. Because of the increased difficulty in managing the number of parts that would require replacement in the event of a crash, the cost of modern cars is more expensive [source: White].
Whether modern cars are less problematic than older ones is a matter of personal opinion. If we mean less problematic for the environment, then the answer is a resounding yes. Are they easier to fix? Certainly. And if that aforementioned 2009 J.D. Power report is any indication, modern cars appear to be growing less problematic for their owners.