Several weeks ago, my wife and I decided to order a model X. After a test drive, we sat in the showroom with the rep and looked at cost of new build. We looked at the inventory also and found an X with the exact same options we wanted plus an additional discount of over $4,000 for being a showroom car. It had yet to be shipped to the showroom (Alabama) and was sitting on a lot in LA. Mileage, like yours, was listed at 50. The rep said it was a new car, we just grabbed it before it could be sent to Alabama. Worked out great for us. Last week, the additional $3,500 was deducted from the sales price. Yours should get the same deduction because of the 100 D battery. So I would say, figure what options you want and look at a new build price and then look around for the exact same car thats in inventory and is listed at 50 miles. The latter choice has worked out better, and cheaper for us. Happy X hunting.
