Really????! I always considered it a testament to engineering if a car (or any device) if it didn't need to be constantly revised. For example, american cars get overhauls every 3-4 years because they aren't well designed to begin with in my opinion.
I'd say that the Porsche 911 is one of the best engineered cars on the road and they update more often than every 5-10 years. IMO, it really isn't so much about the engineering of the car but the comfort and performance level that is associated with new technologies that come out in that period of time. I'd much prefer a company update every 3 years and incorporate new design elements and update features and styling than say its a really well engineered car and not revise for 7 years.