What if Tesla's base model didn't come with a charging port? In other words, they aren't selling you a battery than can be recharged, you can only swap it out (so it essentially remains Tesla's property). It seems like this might allow them to sell the car for $15K-$20K less (since they aren't selling you a usable battery, unless you pay extra for it, in which case you can charge it at home) because you are essentially "renting" the battery (and you pay the "rental" cost every time you swap it for one with a full charge). This also has the considerable benefit of reducing sales tax paid on the vehicle (since it will cost less), along with reduced registration fees. Of course, this requires battery swap stations everywhere, so it isn't going to happen anytime soon. But, if all the existing superchargers were converted to battery swap stations (and significantly more were added in heavily populated areas), a Tesla Model S could potentially cost significantly less, albeit with a cost for getting battery swaps (but still cheaper than a tank of gas, and faster to do). In other words, they'd actually compete, price-wise, with cars like a BMW 5-series and offer the amazing benefit of not requiring gasoline. It seems interesting to me because the idea potentially brings the Model S closer to the price point of a Model 3, and doesn't require the owner to think about or deal with the need for regular charging at home (especially ideal for people who don't own their home, or have a place to set up a charger). The other benefit is that the owner never has to think about the problem of the battery degrading over time (an elephant in the room for many owners, it seems).