As the title says, my wife and I are moving from a model S P100D to a model X 100D. It is just going to be more practical for us since we travel a lot and take our Amazon Parrot with us most of the time. In addition I use a wheelchair so grossing g it I. The hatch of the model S with suitcases and other gear can get tight on extra space. I love the performance side of our model S. I would like to just get the P100D in the X but decided to wait. I don't use the performance side of the car that much but love to have the power when needed. So, can I buy a model X 100D and add the performance side at a later date? I thought the performance was done through the software? Or, are the electric motors different in the model X P100D -VS- 100D. Thanks.