i am interested in getting this question answered as well.
i bought some 17x8 takeoffs from an older X3 (i thought it would fit but now i'm a bit worried).
on a side note, i tirerack seems to have just started carrying the following:
Goodyear Ultra Grip Performance 2 RunOnFlat (
Performance Snow)
in 245/55-17 size. Its one of the only run flats available for 17" that seems to be the right size for an x3 (there is also the blizzak LM50 in 225/60-17, but the load index seems pretty low).
Anyone have thoughts on this?