According to this thread here:
https://f30.bimmerpost.com/forums/sh...d.php?t=901686
... the G09 X8 is unofficially "confirmed" to "exist outside car journos' dreams." The Bimmerpost homepage has this picture of a pre-concept X8 rendering.
Like other even-numbered X models, it appears to be a "coupe" version of the X7. Because there's no dedicated X8 forum here, probably best to discuss it here in the X7 forum.
Me, I'd be VERY interested in this model, based on this assumption: because of the fastback roofline of the X8, I think it'd be unlikely for the X8 to have a 3rd row. (not enough headroom where the 3rd row would be, although in that rendering I think I see a 3rd row headrest, left over from the X7) I'm really disappointed that BMW made the X7 as just an X5-L model, putting every bit of extra length into the 3rd row. So... IF the assumption is true of no 3rd row in the X8, I would hope BMW would instead use the extra length of the X7/X8 and use it just like the 6-series GT, to give the 2nd row 7-series-like luxurious legroom.