When Product Cycles Collide "he auto makers have looked over the fence at the short product cycles of industries like the cellular phone (typical replacement interval 18 months), and are coveting the opportunity to sell someone a new car every two to four years instead of every five to 15. This would attack a trend that's bound to be concerning the auto makers: In 2005, the median age of cars on the road in the United States was almost 9 years, up from 6.5 years in 1990 and 5.1 years in 1969."
I wonder if taking the entire mobile phone model would be good for car makers. They could provide an electric car on a contract and sell access to the required infrastructure. The product cycle probably wouldn't be 18 months but might be less than 9 years (however long those batteries last).