Using the seat memory settings wouldn't have worked on my mirror failure. When the mirror glass position sensor fails, the mirror motor no longer knows where the mirror glass is. That is why it cycles up and down (seemingly randomly, but actually searching....)

Preset positions were no longer held (because it couldn't find them).

I could turn off the auto tilt function and manually move the mirror, but not use the memory settings.

And eventually I just bought the mirror motor assembly, swapped it myself (fairly straightforward) and moved on.

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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