Haven't seen this complaint in a while - it was an epidemic on the E39's, but haven't seen a thread on it on any of the E60, E53, M3 or E70 boards in ages.

FWIW neither our (previous) 2007 X5, or our current 2008 and 2011 X5's creak. (Maybe it's my less-than-svelte physique holding the seat down - try eating more spaghetti and see if that fixes your problems!)

__________________
2011 X5 35D Deep Sea Blue / Oyster
2008 M3 Vert Silverstone II / Black Novillo, 6MT
2008 X5 3.0 Platinum Bronze / Sand Beige Dakota
2007 X5 3.0 Space Gray / Gray Dakota (Retired)