Had the same problem when we ordered out 2013 X1. We followed it through the manufacturing process until it arrived at the dealer, and suddenly they had pictures of it on the web site with exhortations to call for a price etc.
We were horrified. It turns out that when new cars arrive, they automatically photograph them and put them on the web site along with standard blurb to call for pricing. I called and our SA told us it was safe and sound on their showroom floor locked with our name on it. I pointed out that anything more than delivery mileage (5 to 9 miles) would not be acceptable and we would not take delivery if it had more miles, but he said that he would never let a pre-ordered car be either sold or driven as a demo unless we had formally refused the car.
BMW of Austin were extremely good in this respect.
2015 Glacier Silver 428i Gran Coupe
2015 British Racing Green Mini Cooper S 4 Door Hardtop
2012 Space Grey 528i MSport - retired
2013 Valencia Orange X1 xDrive 28i Msport - retired