Many have expressed envy for new features. To enjoy these you have to sell/trade in your car and pay full cost for a new one. The most expensive part of the car is the battery. It is also the component that buyers of used cars worry the most about. What if you could buy a new car minus battery and keep your current battery. They have already demonstrated how quickly batteries can be replaced. Your old car minus the battery could be sold back to tesla. They would then be selling "CPO" cars with new battery raising price on CPO cars or you could sell your old car for parts. The cost would be lower than selling your old car to buy a new one.