X7 does sound like a good idea, and that has been toyed around a lot. They do need a full-size 3 row GL competitor. the 3rd row on the X5 is just not overly practical.
2014 335i RWD: ZMM, ZDA, ZDH, ZPP, ZTP, 2NH, 2TB, 5DL; Z4A MPPK; AW ext / VB int
2014 ML350: P01, R33, 297, 319, 846, 864, 889, 996; LB ext / AB int