This is an interesting idea, but I'd be curious to know what kinds of innovations in car functionality are possible. Also, assuming that you're referring to a kind of planned obsolescence, how can a company convince you to replace the entire vehicle if the moving parts are working fine?

If the computer is broken, replace the computer. Update the self-driving software over the internet. Why would you need to replace the whole car?

Unless, of course, a company tries to integrate points of failure all throughout the body, so that "replacing the computer" of the car or what have you becomes impossible due to the delicate electronic parts. Call me an optimist but at the price of cars today I don't think anyone but the super rich are gullible or decadent enough to fall for something like that instead of a cheaper, more reliable modular alternative. Unless the price of a brand new car becomes similar to that of a new phone, I don't think that future is very likely.