In my opinion, we should keep a car model for 10 years. From my experience, cars change every four years which is too soon. Changing soon requires redrawing, chassis, engine, etc. Too much work. A revolution of a car model will only have a 4 year supply. Fans and Future fans can only buy certain amounts produced. Also, a car is not a toy for pleasure of gifts & design. Its for transportation and thus was drawn in such a fashion.