Sorry if this is obvious, but if I order a non-performance MS with stock 19" wheels (included in price), but wanted the 21" wheels for the summer, wouldn't it be better to order the 21" wheels separately off the Tesla Gear website: http://shop.teslamotors.com/collections/model-s-functional/products/21-grey-performance-wheel , rather than ordering the 21" wheel option with the car (as I wouldn't also receive the 19's)? That is, for an extra $3500, I would be getting the 21s (off their website), but also the 19s with the car -- instead of paying the $3500 for the 21" wheel package with the original wheel order and getting just that set of wheels. Am I missing something?