Cars would probably be a lot safer if they were made more simply, and they didn't change the design ever 2 or 3 years. Stick with time tested designs and get all the bugs out and you'd end up with a car that was reliable and safe.
That is a strong assertion. Can you back that up? Over the years, cars have become safer both for the people inside and other road users (well, the latter probably doesn't really hold for SUV monsters), and also got much better fuel economy. A lot of that you can't achieve by debugging an existing design. Think of aerodynamics and crumple zones, which are integrated into the entire car design. Over here (Netherlands), the minimum age and frequency for mandatory technical inspections of old cars have been relaxed over the years, apparently because of the increase in durability.