On my '06, there is no part 17, unless the diagram is referring to the cloth insulation that is attached to the bottom of the floor panel. Otherwise, the 4.8 just has parts nos. 1 and 7, at least that's how mine is equipped.

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'06 X5 4.8is, TiAg/black, cold weather pkg., comfort seats
'07 750Li, TiAg/black, sport pkg.
'05 Ford F350 silver met./slate gray, Lariat, 6.0 PSD, CC, DRW, FX4