I don't know if it will fit the 3.0, however I seriously doubt it would not fit. I ordered four front rims to use with winter tires. The parts fellow at first tried to discourage me, but as we talked it through he was in agreement the fronts could be installed on the back. As it turned out they fit fine and the vehicle handles great.
Philosophically speaking....Look at all the wierd and outlandishly sized rim combinations people are installing on cars and trucks of all makes. Why on earth would these rims not fit and perform fine on the BMW X5 with a 3.0? My guess is to sell more 4.8's and increase the margin for BMW. It's your money but I think its a safe bet to order the rims.
2013 760 LI 25 Years Edition