Not sure where the OP is located, but given the location tag (similar to a postal code) and the reference to 22,000 km, it may be in Canada. If so, there is no maintenance program on spark plugs unless the plan was purchased separately, just scheduled maintenance (ie oil and filter).

If the dealer is calling for it, it may be a recall on those specific plugs. If so, and they are covering it, go for it. If they want you to pay, ask why you would want to change them so early.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue