from a strictly legal perspective, I think the owners manual (if it states one year intervals are required) takes precedence over any SIB (which is not legally binding on the owner)

They may recall the owners manual and change it, but they cannot change it once they've given it to you. It IS the definitive agreement between buyer and mfg.

My 2 cents.

Find someplace else to do your oil changes anyway.

A

PS I suspect that the right letter, citing the issues correctly, ignoring any "policies" and simply refernceing the contractual commitment by BMW to provide "free maintenance" and the instruction to the owner the the manual that annual service must include an oil change, would result in a 'special consideration'.