Way back in 2002 I took my family to Florida and whilst visiting EPCOT we came across a presentation of the GM EV concept nicknamed the skateboard. This was essentially the essence of an electric vehicle without a body on top. Inspired by the original design of the Mercedes A Class it was a flat sliver containing all the battery and electronics required for an EV with electric motors in the wheels.
It seemed to me to be a great concept. It would allow you to drive up to a particular location, detach your 'cabin' from the chassis and attach to a new fully charged chassis and continue on your journey. Alternatively, for car manufacturers, it would allow them to supply different 'cabins' dependent on what the user needs - a two seater sports, an SUV, an estate car etc. I don't say owner as ownership as a concept would be irrelevant in this model.
Essentially, Tesla have taken this concept and used it to create their own EV architecture.
Now imagine these EV chassis as being autonomous, self contained and completely interchangeable, perhaps within brand and overall vehicle size. Suddenly, you have an EV ecosystem. Maybe you drive a Ford compact EV. This would allow you to choose from say a City Car, 2 seater or small family MPV as you needed, and exchange chassis at an interchange station. Or maybe you have a Jaguar large EV, allowing you to choose a large family saloon, large MPV or commercial van chassis.
http://evworld.com/article.cfm?storyid=286This Forbes article is a good read, giving some history and some images of the things I have been discussing here.
https://www.forbes.com/sites/samabuelsamid/2016/05/23/the-father-of-the-skateboard-chassis-dr-chris-borroni-bird/#52e6abbf7b30